fix(verifier): add changeOrigin flag for http-proxy

* add changeOrigin flag for http-proxy and update readme
* amend changeOrigin check as it was incorrect

Fixes #282

README.md

@@ -299,6 +299,8 @@ new Verifier().verifyProvider(opts).then(function () {
 | `timeout`                   |  false   | number           | The duration in ms we should wait to confirm verification process was successful. Defaults to 30000.                                                                                                                                             |
 | `requestFilter`             |  false   | object           | An Express middleware handler (See https://expressjs.com/en/guide/writing-middleware.html) to modify requests and responses from the provider. See below for more details.                                                                       |
 | `stateHandlers`             |  false   | object           | Provider state handlers. A map of `string` -> `() => Promise`, where each string is the state to setup, and the function is used to configure the state in the Provider. See below for detail.                                                   |
+| `validateSSL`               |  false   | boolean          | Allow self-signed certificates. Defaults to true, if not set.                                                                                                                                                                                     |
+| `changeOrigin`              |  false   | boolean          | Changes the origin of the host header to the target URL. Defaults to false, if not set.                                                                                                                                                                                    |
 
 </details>
 
@@ -341,7 +343,7 @@ Sometimes you may need to add things to the requests that can't be persisted in
 For these cases, we have two facilities that should be carefully used during verification:
 
 1. the ability to specify custom headers to be sent during provider verification. The flag to achieve this is `customProviderHeaders`.
-1. the ability to modify a request/response and modify the payload. The flag to achieve this is `requestFilter`.
+2. the ability to modify a request/response and modify the payload. The flag to achieve this is `requestFilter`.
 
 **Example API with Authorization**
 

src/dsl/verifier.ts

@@ -48,6 +48,7 @@ export interface VerifierOptions {
   format?: "json" | "RspecJunitFormatter"
   out?: string
   validateSSL?: boolean
+  changeOrigin?: boolean
 }
 
 export class Verifier {
@@ -156,6 +157,7 @@ export class Verifier {
     app.all("/*", (req, res) => {
       logger.debug("Proxing", req.path)
       proxy.web(req, res, {
+        changeOrigin: this.config.changeOrigin === true,
         secure: this.config.validateSSL === true,
         target: this.config.providerBaseUrl,
       })
@@ -209,6 +211,9 @@ export class Verifier {
     if (this.config.validateSSL === undefined) {
       this.config.validateSSL = true
     }
+    if (this.config.changeOrigin === undefined) {
+      this.config.changeOrigin = false
+    }
 
     if (this.config.logLevel && !isEmpty(this.config.logLevel)) {
       serviceFactory.logLevel(this.config.logLevel)