Merge pull request #2733 from hennevogel/feature/sentry

Introduces sentry, removes airbrake

Gemfile.lock

@@ -68,10 +68,6 @@ GEM
     addressable (2.6.0)
       public_suffix (>= 2.0.2, < 4.0)
     afm (0.2.2)
-    airbrake (9.2.2)
-      airbrake-ruby (~> 4.4)
-    airbrake-ruby (4.4.0)
-      rbtree3 (~> 0.5)
     ajax-datatables-rails (0.4.3)
       railties (>= 4.0)
     archive-zip (0.12.0)
@@ -446,7 +442,6 @@ GEM
     rb-fsevent (0.10.3)
     rb-inotify (0.10.0)
       ffi (~> 1.0)
-    rbtree3 (0.5.0)
     recaptcha (4.14.0)
       json
     redcarpet (3.5.1)
@@ -526,6 +521,12 @@ GEM
     selenium-webdriver (3.142.6)
       childprocess (>= 0.5, < 4.0)
       rubyzip (>= 1.2.2)
+    sentry-rails (4.2.2)
+      rails (>= 5.0)
+      sentry-ruby-core (~> 4.2.0)
+    sentry-ruby-core (4.2.2)
+      concurrent-ruby
+      faraday
     sexp_processor (4.11.0)
     shellany (0.0.1)
     shoulda-matchers (4.1.2)
@@ -617,7 +618,6 @@ DEPENDENCIES
   active_model_serializers
   acts_as_commentable_with_threading
   acts_as_list
-  airbrake
   ajax-datatables-rails
   autoprefixer-rails
   awesome_nested_set
@@ -707,6 +707,7 @@ DEPENDENCIES
   ruby-oembed
   sass-rails (>= 4.0.2)
   selectize-rails
+  sentry-rails
   shoulda-matchers
   simplecov-cobertura
   skylight