Aborted network requests should use protocol's "Failed" status (#215)

This patch starts using "Failed" command for request interception instead of
"Aborted".

The "Aborted" status also has a side-effect of cancelling the navigation, so
there will be no error on the page and form puppeteer's standpoint, the navigation
will never complete.

lib/NetworkManager.js

@@ -243,7 +243,7 @@ class InterceptedRequest {
     this._handled = true;
     this._client.send('Network.continueInterceptedRequest', {
       interceptionId: this._interceptionId,
-      errorReason: 'Aborted'
+      errorReason: 'Failed'
     });
   }
 

test/test.js

@@ -770,6 +770,17 @@ describe('Page', function() {
       ]);
       expect(request.headers['foo']).toBe('bar');
     }));
+    it('should fail navigation when aborting main resource', SX(async function() {
+      page.setRequestInterceptor(request => request.abort());
+      let error = null;
+      try {
+        await page.navigate(EMPTY_PAGE);
+      } catch (e) {
+        error = e;
+      }
+      expect(error).toBeTruthy();
+      expect(error.message).toContain('Failed to navigate');
+    }));
   });
 
   describe('Page.Events.Dialog', function() {