[Security] Bump paperclip from 5.1.0 to 6.1.0

Bumps [paperclip](https://github.com/thoughtbot/paperclip) from 5.1.0 to 6.1.0. **This update includes security fixes.**
- [Release notes](https://github.com/thoughtbot/paperclip/releases)
- [Changelog](https://github.com/thoughtbot/paperclip/blob/master/NEWS)
- [Commits](thoughtbot/paperclip@v5.1.0...v6.1.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Author: dependabot-support

Gemfile

@@ -36,7 +36,7 @@ gem "twitter-text" # hashtag parsing
 gem "jquery-atwho-rails", "~> 1.3.2" # autocomplete
 gem "haml-rails"
 gem "audited-activerecord", "~> 4.0"
-gem "paperclip", "~> 5.1.0"
+gem "paperclip", "~> 6.1.0"
 gem "aws-sdk"
 gem "redcarpet"
 gem "holidays"

Gemfile.lock

@@ -623,8 +623,6 @@ GEM
       capybara (>= 2.0.2, < 2.4.0)
       json
     climate_control (0.2.0)
-    cocaine (0.5.8)
-      climate_control (>= 0.0.3, < 1.0)
     coderay (1.1.0)
     coffee-rails (4.0.1)
       coffee-script (>= 2.2.0)
@@ -718,9 +716,9 @@ GEM
       mini_mime (>= 0.1.1)
     memcachier (0.0.2)
     method_source (0.8.2)
-    mime-types (3.1)
+    mime-types (3.2.2)
       mime-types-data (~> 3.2015)
-    mime-types-data (3.2016.0521)
+    mime-types-data (3.2018.0812)
     mimemagic (0.3.2)
     mini_mime (1.0.0)
     mini_portile2 (2.3.0)
@@ -736,12 +734,12 @@ GEM
       mini_portile2 (~> 2.3.0)
     normalize-rails (3.0.1)
     orm_adapter (0.5.0)
-    paperclip (5.1.0)
+    paperclip (6.1.0)
       activemodel (>= 4.2.0)
       activesupport (>= 4.2.0)
-      cocaine (~> 0.5.5)
       mime-types
       mimemagic (~> 0.3.0)
+      terrapin (~> 0.6.0)
     pg (0.18.4)
     pikaday-gem (1.2.0)
       railties (>= 3.1)
@@ -854,6 +852,8 @@ GEM
       sprockets (>= 3.0.0)
     temple (0.7.6)
     terminal-table (1.5.2)
+    terrapin (0.6.0)
+      climate_control (>= 0.0.3, < 1.0)
     thor (0.19.4)
     thread_safe (0.3.6)
     tilt (2.0.5)
@@ -925,7 +925,7 @@ DEPENDENCIES
   neat
   newrelic_rpm (>= 3.7.3)
   normalize-rails
-  paperclip (~> 5.1.0)
+  paperclip (~> 6.1.0)
   pg
   pikaday-gem (~> 1.2.0.0)
   pry