Stop depending on mimemagic

mimemagic was yanked due to licencing issues. We've forked paperclip
to remove the mimemagic dependency to be able to keep building the
project.

See thoughtbot/paperclip#2678

Gemfile

@@ -13,7 +13,7 @@ gem 'decent_exposure'
 gem 'nokogiri', '~> 1.6.7.2'
 gem 'react-rails', '~> 1.3.2'
 gem 'foreman'
-gem 'paperclip', '~> 4.3.6'
+gem 'paperclip', git: 'https://github.com/instedd/paperclip', branch: 'fix/v4.3.6-no-mimemagic'
 gem 'aws-sdk', '~> 1.6'
 gem 'newrelic_rpm'
 gem 'paranoia'

Gemfile.lock

@@ -13,6 +13,17 @@ GIT
   specs:
     geojson_import (0.0.2)
 
+GIT
+  remote: https://github.com/instedd/paperclip
+  revision: 909ed091f80c763f9da8ae6cca4f2a93e49d7a69
+  branch: fix/v4.3.6-no-mimemagic
+  specs:
+    paperclip (4.3.6)
+      activemodel (>= 3.2.0)
+      activesupport (>= 3.2.0)
+      cocaine (~> 0.5.5)
+      mime-types
+
 GIT
   remote: https://github.com/instedd/poirot_rails.git
   revision: c3e8ceeacd07a226b941a8cabb2dd762fa73846f
@@ -190,8 +201,7 @@ GEM
     childprocess (0.5.9)
       ffi (~> 1.0, >= 1.0.11)
     chunky_png (1.3.1)
-    climate_control (0.0.3)
-      activesupport (>= 3.0)
+    climate_control (0.2.0)
     clipboard (1.0.6)
     cliver (0.3.2)
     cocaine (0.5.8)
@@ -363,7 +373,6 @@ GEM
       webrobots (>= 0.0.9, < 0.2)
     method_source (0.8.2)
     mime-types (2.99.1)
-    mimemagic (0.3.0)
     mini_portile2 (2.0.0)
     minitest (5.8.4)
     multi_json (1.11.2)
@@ -405,12 +414,6 @@ GEM
       oauth2 (~> 1.0)
       omniauth (~> 1.2)
     orm_adapter (0.5.0)
-    paperclip (4.3.6)
-      activemodel (>= 3.2.0)
-      activesupport (>= 3.2.0)
-      cocaine (~> 0.5.5)
-      mime-types
-      mimemagic (= 0.3.0)
     paranoia (2.1.4)
       activerecord (~> 4.0)
     poltergeist (1.7.0)
@@ -692,7 +695,7 @@ DEPENDENCIES
   oj
   omniauth
   omniauth-google-oauth2
-  paperclip (~> 4.3.6)
+  paperclip!
   paranoia
   poirot_rails!
   poltergeist
@@ -737,4 +740,4 @@ DEPENDENCIES
   webmock
 
 BUNDLED WITH
-   1.11.2
+   1.16.1