Update NPM dependencies

[wolfpilot]

This PR will:

• Fix a bunch of JS linting errors that were previously unchecked, including a bit of refactoring of the getDataPath() function (nunjucks-extensions.js).
• Update all dependencies to their latest versions, details below.

Notes:

• gulp-sass v3.5+ throws deprecation warnings about .css files not being importable in the future unless using custom CSS importers. Reason's that gulp-sass is indirectly based on libsass which introduced this change around end of March 2018 (link1, link2).
• gulp-stylelint now requires stylelint as a separate dependency.
• uglify-js v3 simplified their API which made it entirely non-backwards compatible with uglify-js@2, so I had to update some code according to the new API.

As far as I'm aware, all gulp tasks work correctly, I tested all of them throughout and at the end of the update to make sure everything's ok.

Now... can we get that dependencies badge already? 😄

[branneman]

Works fine on the current LTS (v8), but not on Stable (v10). I'm not sure if we can fix that, it'll probably start working soon. What say you?

An npm i on Node.js v10.2.0 fails:

/Users/bvandermeer/.node-gyp/10.2.0/include/node/node.h:53:10: fatal error: 'core.h' file not found
#include "core.h"  // NOLINT(build/include_order)
         ^~~~~~~~
1 error generated.
make: *** [Release/obj.target/binding/src/binding.o] Error 1
gyp ERR! build error
gyp ERR! stack Error: `make` failed with exit code: 2
gyp ERR! stack     at ChildProcess.onExit (/Users/bvandermeer/Source/frontend-boilerplate-razvan/node_modules/node-gyp/lib/build.js:258:23)
gyp ERR! stack     at ChildProcess.emit (events.js:182:13)
gyp ERR! stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:237:12)
gyp ERR! System Darwin 17.5.0
gyp ERR! command "/Users/bvandermeer/.nvm/versions/node/v10.2.0/bin/node" "/Users/bvandermeer/Source/frontend-boilerplate-razvan/node_modules/node-gyp/bin/node-gyp.js" "rebuild" "--verbose" "--libsass_ext=" "--libsass_cflags=" "--libsass_ldflags=" "--libsass_library="
gyp ERR! cwd /Users/bvandermeer/Source/frontend-boilerplate-razvan/node_modules/node-sass
gyp ERR! node -v v10.2.0
gyp ERR! node-gyp -v v3.6.2
gyp ERR! not ok
Build failed with error code: 1
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.1.3 (node_modules/fsevents):
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.1.3 install: `node install`
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: Exit status 1

An npm run dev on Node.js v10.0.0 fails:

$ npm run dev

> frontend-boilerplate@1.0.0 dev /.../frontend-boilerplate-wolfpilot
> node node_modules/gulp/bin/gulp.js dev

[13:49:12] Requiring external module babel-core/register
gulp[41987]: ../src/node_contextify.cc:631:static void node::contextify::ContextifyScript::New(const FunctionCallbackInfo<v8::Value> &): Assertion `args[1]->IsString()' failed.
 1: node::Abort() [/Users/bvandermeer/.nvm/versions/node/v10.0.0/bin/node]
 2: node::InternalCallbackScope::~InternalCallbackScope() [/Users/bvandermeer/.nvm/versions/node/v10.0.0/bin/node]
 3: node::contextify::ContextifyScript::New(v8::FunctionCallbackInfo<v8::Value> const&) [/Users/bvandermeer/.nvm/versions/node/v10.0.0/bin/node]
 4: v8::internal::FunctionCallbackArguments::Call(v8::internal::CallHandlerInfo*) [/Users/bvandermeer/.nvm/versions/node/v10.0.0/bin/node]
 5: v8::internal::MaybeHandle<v8::internal::Object> v8::internal::(anonymous namespace)::HandleApiCallHelper<true>(v8::internal::Isolate*, v8::internal::Handle<v8::internal::HeapObject>, v8::internal::Handle<v8::internal::HeapObject>, v8::internal::Handle<v8::internal::FunctionTemplateInfo>, v8::internal::Handle<v8::internal::Object>, v8::internal::BuiltinArguments) [/Users/bvandermeer/.nvm/versions/node/v10.0.0/bin/node]
 6: v8::internal::Builtin_Impl_HandleApiCall(v8::internal::BuiltinArguments, v8::internal::Isolate*) [/Users/bvandermeer/.nvm/versions/node/v10.0.0/bin/node]
 7: 0x3cfa85c8427d

[wolfpilot]

@branneman First issue looks related to a broken Node v10.2.0 release - link. A hotfix is in the works and will be pushed soon, so you can wait and try again after that :)

Not sure about v10.0.0 not compiling. Have you tried deleting node_modules and running install again?

[branneman]

Yea, I've tried rm -rf node_modules, npm rebuild and npm i --build-from-source

[peeke]

Updated my existing projects modules and fixed the errors with your updated uglifyjs code. Instead of normalize-scss we used normalize-libsass. (Not using stylelint). Will test a clean copy pasta of your PR into the project right now.

[Thomas-Machielsen]

Am a bit late to the party but I read through all the updated packages their npm pages, only uglyfi-js is not backwards compatible. Don't think that's much of an issue. I also ran the linter and there are no errors, so I'd approve this pull request.

[peeke]

Tested this in an existing project with Node v8.11.1 and v10.0.0, works fine 👍
Also, ran ncu -u again, there are 4 updates since the last changes. They seem to cause no problems, but maybe let's get this one merged first :)