Add support for requestInterceptor / responseInterceptor.

- Display mutated requests from request interceptor in curl output in UI.
  Put this behind showMutatedRequest flag so that the mutation can be
  silent.
- Document requestInterceptor, responseInterceptor and showMutatedRequest
  in README.md
- Add tests

src/core/components/live-response.jsx

@@ -29,13 +29,18 @@ Duration.propTypes = {
 export default class LiveResponse extends React.Component {
   static propTypes = {
     response: PropTypes.object.isRequired,
+    specSelectors: PropTypes.object.isRequired,
+    pathMethod: PropTypes.object.isRequired,
     getComponent: PropTypes.func.isRequired,
-    displayRequestDuration: PropTypes.bool.isRequired
+    displayRequestDuration: PropTypes.bool.isRequired,
+    getConfigs: PropTypes.func.isRequired
   }
 
   render() {
-    const { request, response, getComponent, displayRequestDuration } = this.props
+    const { response, getComponent, getConfigs, displayRequestDuration, specSelectors, pathMethod } = this.props
+    const { showMutatedRequest } = getConfigs()
 
+    const curlRequest = showMutatedRequest ? specSelectors.mutatedRequestFor(pathMethod[0], pathMethod[1]) : specSelectors.requestFor(pathMethod[0], pathMethod[1])
     const status = response.get("status")
     const url = response.get("url")
     const headers = response.get("headers").toJS()
@@ -55,7 +60,7 @@ export default class LiveResponse extends React.Component {
 
     return (
       <div>
-        { request && <Curl request={ request }/> }
+        { curlRequest && <Curl request={ curlRequest }/> }
         <h4>Server response</h4>
         <table className="responses-table">
           <thead>

src/core/components/operation.jsx

@@ -263,6 +263,7 @@ export default class Operation extends PureComponent {
                     request={ request }
                     tryItOutResponse={ response }
                     getComponent={ getComponent }
+                    getConfigs={ getConfigs }
                     specSelectors={ specSelectors }
                     specActions={ specActions }
                     produces={ produces }

src/core/components/responses.jsx

@@ -16,7 +16,8 @@ export default class Responses extends React.Component {
     specActions: PropTypes.object.isRequired,
     pathMethod: PropTypes.array.isRequired,
     displayRequestDuration: PropTypes.bool.isRequired,
-    fn: PropTypes.object.isRequired
+    fn: PropTypes.object.isRequired,
+    getConfigs: PropTypes.func.isRequired
   }
 
   static defaultProps = {
@@ -29,7 +30,7 @@ export default class Responses extends React.Component {
   onChangeProducesWrapper = ( val ) => this.props.specActions.changeProducesValue(this.props.pathMethod, val)
 
   render() {
-    let { responses, request, tryItOutResponse, getComponent, specSelectors, fn, producesValue, displayRequestDuration } = this.props
+    let { responses, request, tryItOutResponse, getComponent, getConfigs, specSelectors, fn, producesValue, displayRequestDuration } = this.props
     let defaultCode = defaultStatusCode( responses )
 
     const ContentType = getComponent( "contentType" )
@@ -57,6 +58,9 @@ export default class Responses extends React.Component {
                                   <LiveResponse request={ request }
                                                 response={ tryItOutResponse }
                                                 getComponent={ getComponent }
+                                                getConfigs={ getConfigs }
+                                                specSelectors={ specSelectors }
+                                                pathMethod={ this.props.pathMethod }
                                                 displayRequestDuration={ displayRequestDuration } />
                                   <h4>Responses</h4>
                                 </div>