Fix #61 - Add list of blocked users to the UI; clean up failed push notifications API

Try to fix Travis CI setup

.travis.yml

@@ -11,7 +11,7 @@ env:
     - LOCAL_DOMAIN=cb6e6126.ngrok.io
     - LOCAL_HTTPS=true
     - RAILS_ENV=test
-
+    - CXX=g++-4.8
 addons:
   postgresql: 9.4
 
@@ -23,6 +23,10 @@ services:
 
 bundler_args: --without development production --retry=3 --jobs=3
 
+before_install:
+  - sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test
+  - sudo apt-get -qq update
+  - sudo apt-get -qq install g++-4.8
 install:
   - nvm install $TRAVIS_NODE_VERSION
   - npm install -g npm@3