Refactor specPath to Im data structures to avoid waste renders

src/core/components/responses.jsx

@@ -1,6 +1,7 @@
 import React from "react"
-import PropTypes from "prop-types"
 import { fromJS, Iterable } from "immutable"
+import PropTypes from "prop-types"
+import ImPropTypes from "react-immutable-proptypes"
 import { defaultStatusCode, getAcceptControllingResponse } from "core/utils"
 
 export default class Responses extends React.Component {
@@ -17,7 +18,7 @@ export default class Responses extends React.Component {
     specSelectors: PropTypes.object.isRequired,
     specActions: PropTypes.object.isRequired,
     oas3Actions: PropTypes.object.isRequired,
-    specPath: PropTypes.array.isRequired,
+    specPath: ImPropTypes.list.isRequired,
     fn: PropTypes.object.isRequired
   }
 
@@ -120,7 +121,7 @@ export default class Responses extends React.Component {
                   let className = tryItOutResponse && tryItOutResponse.get("status") == code ? "response_current" : ""
                   return (
                     <Response key={ code }
-                              specPath={[...specPath, code]}
+                              specPath={specPath.push(code)}
                               isDefault={defaultCode === code}
                               fn={fn}
                               className={ className }