Explicitly exclude bower_components in polylint

This was included in the iron-input change earlier that has since been
reverted.

Also replace deprecated bindValue with value in gr-textarea.

Bug: Issue 6862
Change-Id: I54d17cbf26d92b987aab9f71a98c738f168ff416

polygerrit-ui/app/elements/shared/gr-textarea/gr-textarea.html

@@ -71,7 +71,7 @@ limitations under the License.
         disabled="[[disabled]]"
         rows="[[rows]]"
         max-rows="[[maxRows]]"
-        bind-value="{{text}}"
+        value="{{text}}"
         on-bind-value-changed="_onValueChanged"></iron-autogrow-textarea>
   </template>
   <script src="gr-textarea.js"></script>

polygerrit-ui/app/polylint_test.sh

@@ -17,4 +17,4 @@ fi
 
 unzip polygerrit-ui/polygerrit_components.bower_components.zip -d polygerrit-ui/app
 
-${polylint_bin} --root polygerrit-ui/app --input elements/gr-app.html
+${polylint_bin} --root polygerrit-ui/app --input elements/gr-app.html --b 'bower_components'