fix(webpack-dev-server): Lock version to 3.2.1 (#348)

There is an issue with the latest version of `webpack-dev-server` (v3.3.1) working in `sku`. We should look at this issue but I think it may be on their end. Either way this PR ensures users don't upgrade and get errors. 

Example error.
```bash
$ npm start

> my-app@0.1.0 start /Users/gkljajic/projects/my-app
> sku start


Starting the development server on http://localhost:8080/

ℹ ｢wdm｣: wait until bundle finished: /
🚨 HtmlRenderPlugin: An error occured rendering HTML ReferenceError: self is not defined
    at Object.eval (webpack://static/(webpack)-dev-server/client?:51:19)
    at eval (webpack://static/(webpack)-dev-server/client?:299:30)
    at Object../node_modules/webpack-dev-server/client/index.js?http://localhost (render.js:2532:1)
    at __webpack_require__ (render.js:30:30)
    at eval (webpack://static/multi_(webpack)-dev-server/client?:1:1)
    at Object.0 (render.js:2624:1)
    at __webpack_require__ (render.js:30:30)
    at render.js:94:18
    at render.js:97:10
    at webpackUniversalModuleDefinition (render.js:3:20)
✖ ｢wdm｣: Child client:

    ERROR in html-render-webpack-plugin: An error occured during render:
    ReferenceError: self is not defined
ℹ ｢wdm｣: Failed to compile.
```

package.json

@@ -161,7 +161,7 @@
     "validate-npm-package-name": "^3.0.0",
     "webpack": "^4.28.2",
     "webpack-bundle-analyzer": "^3.0.2",
-    "webpack-dev-server": "^3.1.14",
+    "webpack-dev-server": "3.2.1",
     "webpack-merge": "^4.1.5",
     "webpack-node-externals": "^1.7.2"
   },

yarn.lock

@@ -3625,7 +3625,26 @@ child-process-promise@^2.2.1:
     node-version "^1.0.0"
     promise-polyfill "^6.0.1"
 
-chokidar@^2.0.0, chokidar@^2.0.2:
+chokidar@^2.0.0:
+  version "2.1.5"
+  resolved "https://registry.yarnpkg.com/chokidar/-/chokidar-2.1.5.tgz#0ae8434d962281a5f56c72869e79cb6d9d86ad4d"
+  integrity sha512-i0TprVWp+Kj4WRPtInjexJ8Q+BqTE909VpH8xVhXrJkoc5QC8VO9TryGOqTr+2hljzc1sC62t22h5tZePodM/A==
+  dependencies:
+    anymatch "^2.0.0"
+    async-each "^1.0.1"
+    braces "^2.3.2"
+    glob-parent "^3.1.0"
+    inherits "^2.0.3"
+    is-binary-path "^1.0.0"
+    is-glob "^4.0.0"
+    normalize-path "^3.0.0"
+    path-is-absolute "^1.0.0"
+    readdirp "^2.2.1"
+    upath "^1.1.1"
+  optionalDependencies:
+    fsevents "^1.2.7"
+
+chokidar@^2.0.2:
   version "2.1.2"
   resolved "https://registry.yarnpkg.com/chokidar/-/chokidar-2.1.2.tgz#9c23ea40b01638439e0513864d362aeacc5ad058"
   integrity sha512-IwXUx0FXc5ibYmPC2XeEj5mpXoV66sR+t3jqu2NS2GYwCktt3KF1/Qqjws/NkegajBA4RbZ5+DDwlOiJsxDHEg==
@@ -3982,23 +4001,23 @@ component-emitter@^1.2.1:
   resolved "https://registry.yarnpkg.com/component-emitter/-/component-emitter-1.2.1.tgz#137918d6d78283f7df7a6b7c5a63e140e69425e6"
   integrity sha1-E3kY1teCg/ffemt8WmPhQOaUJeY=
 
-compressible@~2.0.14:
+compressible@~2.0.16:
   version "2.0.16"
   resolved "https://registry.yarnpkg.com/compressible/-/compressible-2.0.16.tgz#a49bf9858f3821b64ce1be0296afc7380466a77f"
   integrity sha512-JQfEOdnI7dASwCuSPWIeVYwc/zMsu/+tRhoUvEfXz2gxOA2DNjmG5vhtFdBlhWPPGo+RdT9S3tgc/uH5qgDiiA==
   dependencies:
     mime-db ">= 1.38.0 < 2"
 
 compression@^1.5.2:
-  version "1.7.3"
-  resolved "https://registry.yarnpkg.com/compression/-/compression-1.7.3.tgz#27e0e176aaf260f7f2c2813c3e440adb9f1993db"
-  integrity sha512-HSjyBG5N1Nnz7tF2+O7A9XUhyjru71/fwgNb7oIsEVHR0WShfs2tIS/EySLgiTe98aOK18YDlMXpzjCXY/n9mg==
+  version "1.7.4"
+  resolved "https://registry.yarnpkg.com/compression/-/compression-1.7.4.tgz#95523eff170ca57c29a0ca41e6fe131f41e5bb8f"
+  integrity sha512-jaSIDzP9pZVS4ZfQ+TzvtiWhdpFhE2RDHz8QJkpX9SIpLq88VueF5jJw6t+6CUQcAoA6t+x89MLrWAqpfDE8iQ==
   dependencies:
     accepts "~1.3.5"
     bytes "3.0.0"
-    compressible "~2.0.14"
+    compressible "~2.0.16"
     debug "2.6.9"
-    on-headers "~1.0.1"
+    on-headers "~1.0.2"
     safe-buffer "5.1.2"
     vary "~1.1.2"
 
@@ -10352,7 +10371,7 @@ on-finished@~2.3.0:
   dependencies:
     ee-first "1.1.1"
 
-on-headers@~1.0.1:
+on-headers@~1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/on-headers/-/on-headers-1.0.2.tgz#772b0ae6aaa525c399e489adfad90c403eb3c28f"
   integrity sha512-pZAE+FJLoyITytdqK0U5s+FIpjN0JP3OzFi/u8Rx+EV5/W+JTWGXG8xFzevE7AjBfDqHv/8vL8qQsIhHnqRkrA==
@@ -10381,13 +10400,20 @@ openurl@1.1.1:
   resolved "https://registry.yarnpkg.com/openurl/-/openurl-1.1.1.tgz#3875b4b0ef7a52c156f0db41d4609dbb0f94b387"
   integrity sha1-OHW0sO96UsFW8NtB1GCduw+Us4c=
 
-opn@5.4.0, opn@^5.1.0, opn@^5.3.0, opn@^5.4.0:
+opn@5.4.0, opn@^5.3.0, opn@^5.4.0:
   version "5.4.0"
   resolved "https://registry.yarnpkg.com/opn/-/opn-5.4.0.tgz#cb545e7aab78562beb11aa3bfabc7042e1761035"
   integrity sha512-YF9MNdVy/0qvJvDtunAOzFw9iasOQHpVthTCvGzxt61Il64AYSGdK+rYwld7NAfk9qJ7dt+hymBNSc9LNYS+Sw==
   dependencies:
     is-wsl "^1.1.0"
 
+opn@^5.1.0:
+  version "5.5.0"
+  resolved "https://registry.yarnpkg.com/opn/-/opn-5.5.0.tgz#fc7164fab56d235904c51c3b27da6758ca3b9bfc"
+  integrity sha512-PqHpggC9bLV0VeWcdKhkpxY+3JTzetLSqTCWL/z/tFIbI6G8JCjondXklT1JinczLz2Xib62sSp0T/gKT4KksA==
+  dependencies:
+    is-wsl "^1.1.0"
+
 optimist@^0.6.1:
   version "0.6.1"
   resolved "https://registry.yarnpkg.com/optimist/-/optimist-0.6.1.tgz#da3ea74686fa21a19a111c326e90eb15a0196686"
@@ -14374,6 +14400,11 @@ upath@^1.1.0:
   resolved "https://registry.yarnpkg.com/upath/-/upath-1.1.0.tgz#35256597e46a581db4793d0ce47fa9aebfc9fabd"
   integrity sha512-bzpH/oBhoS/QI/YtbkqCg6VEiPYjSZtrHQM6/QnJS6OL9pKUFLqb3aFh4Scvwm45+7iAgiMkLhSbaZxUqmrprw==
 
+upath@^1.1.1:
+  version "1.1.2"
+  resolved "https://registry.yarnpkg.com/upath/-/upath-1.1.2.tgz#3db658600edaeeccbe6db5e684d67ee8c2acd068"
+  integrity sha512-kXpym8nmDmlCBr7nKdIx8P2jNBa+pBpIUFRnKJ4dr8htyYGJFokkr2ZvERRtUN+9SY+JqXouNgUPtv6JQva/2Q==
+
 update-notifier@^2.3.0, update-notifier@^2.5.0:
   version "2.5.0"
   resolved "https://registry.yarnpkg.com/update-notifier/-/update-notifier-2.5.0.tgz#d0744593e13f161e406acb1d9408b72cad08aff6"
@@ -14707,7 +14738,7 @@ webpack-bundle-analyzer@^3.0.2:
     opener "^1.5.1"
     ws "^6.0.0"
 
-webpack-dev-middleware@^3.4.0, webpack-dev-middleware@^3.5.1:
+webpack-dev-middleware@^3.4.0:
   version "3.6.0"
   resolved "https://registry.yarnpkg.com/webpack-dev-middleware/-/webpack-dev-middleware-3.6.0.tgz#71f1b04e52ff8d442757af2be3a658237d53a3e5"
   integrity sha512-oeXA3m+5gbYbDBGo4SvKpAHJJEGMoekUbHgo1RK7CP1sz7/WOSeu/dWJtSTk+rzDCLkPwQhGocgIq6lQqOyOwg==
@@ -14717,7 +14748,17 @@ webpack-dev-middleware@^3.4.0, webpack-dev-middleware@^3.5.1:
     range-parser "^1.0.3"
     webpack-log "^2.0.0"
 
-webpack-dev-server@^3.1.14:
+webpack-dev-middleware@^3.5.1:
+  version "3.6.2"
+  resolved "https://registry.yarnpkg.com/webpack-dev-middleware/-/webpack-dev-middleware-3.6.2.tgz#f37a27ad7c09cd7dc67cd97655413abaa1f55942"
+  integrity sha512-A47I5SX60IkHrMmZUlB0ZKSWi29TZTcPz7cha1Z75yYOsgWh/1AcPmQEbC8ZIbU3A1ytSv1PMU0PyPz2Lmz2jg==
+  dependencies:
+    memory-fs "^0.4.1"
+    mime "^2.3.1"
+    range-parser "^1.0.3"
+    webpack-log "^2.0.0"
+
+webpack-dev-server@3.2.1:
   version "3.2.1"
   resolved "https://registry.yarnpkg.com/webpack-dev-server/-/webpack-dev-server-3.2.1.tgz#1b45ce3ecfc55b6ebe5e36dab2777c02bc508c4e"
   integrity sha512-sjuE4mnmx6JOh9kvSbPYw3u/6uxCLHNWfhWaIPwcXWsvWOPN+nc5baq4i9jui3oOBRXGonK9+OI0jVkaz6/rCw==