Bug 1404891 - Add noProxy documentation for proxy capabilities. r=ato

We missed adding it for the implementation on bug 1387094.

DONTBUILD

MozReview-Commit-ID: E717NEO7o2U

--HG--
extra : rebase_source : facb28d006e514bff6796f8c0e085c73f313d0ce

testing/geckodriver/README.md

@@ -163,6 +163,14 @@ geckodriver supports a number of [capabilities]:
    is set to <code>manual</code>.
  </tr>
 
+ <tr>
+  <td><code>noProxy</code>
+  <td>list
+  <td>Lists the addresses for which the proxy should be bypassed.
+   This property should only be set when <code>proxyType</code>
+   is set to <code>manual</code>.
+ </tr>
+
  <tr>
   <td><code>sslProxy</code>
   <td>string