Constrain cookies to the root path

Setting the cookie on the "/" path will make the token available on all pages of
the web application.  This fixes the bug where you had to log in every time the
page was reloaded.

Change-Id: I1a09c140f8060f463c2f36fdd673153a0e575944
Closes-Bug: #1680547

releasenotes/notes/constrain-cookies-04157d770782e692.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    Fixes `bug 1680547 <https://launchpad.net/bugs/1680547>`__
+    Fix a bug where you had to log into the application on every page reload

src/js/actions/LoginActions.js

@@ -13,7 +13,9 @@ export default {
     return (dispatch, getState) => {
       dispatch(this.userAuthStarted());
       KeystoneApiService.authenticateUserViaToken(keystoneAuthTokenId).then((response) => {
-        cookie.save('keystoneAuthTokenId', response.access.token.id);
+        cookie.save('keystoneAuthTokenId',
+                    response.access.token.id,
+                    { path: '/' });
         dispatch(this.userAuthSuccess(response.access));
         ZaqarWebSocketService.init(getState, dispatch);
         browserHistory.push(nextPath);
@@ -31,7 +33,9 @@ export default {
     return (dispatch, getState) => {
       dispatch(this.userAuthStarted());
       KeystoneApiService.authenticateUser(formData.username, formData.password).then((response) => {
-        cookie.save('keystoneAuthTokenId', response.access.token.id);
+        cookie.save('keystoneAuthTokenId',
+                    response.access.token.id,
+                    { path: '/' });
         dispatch(this.userAuthSuccess(response.access));
         ZaqarWebSocketService.init(getState, dispatch);
         browserHistory.push(nextPath);