API param to exclude notification types from response (#1341)

* Add exclude_types param to /api/v1/notifications

* Exclude notification types in web UI through exclude_types in the API

Gemfile.lock

@@ -286,6 +286,10 @@ GEM
       bundler (>= 1.3.0, < 2.0)
       railties (= 5.0.2)
       sprockets-rails (>= 2.0.0)
+    rails-controller-testing (1.0.1)
+      actionpack (~> 5.x)
+      actionview (~> 5.x)
+      activesupport (~> 5.x)
     rails-dom-testing (2.0.2)
       activesupport (>= 4.2.0, < 6.0)
       nokogiri (~> 1.6)
@@ -487,6 +491,7 @@ DEPENDENCIES
   rack-cors
   rack-timeout
   rails (~> 5.0.2)
+  rails-controller-testing
   rails-settings-cached
   rails_12factor
   react-rails