Revert "Install `mailcatcher` in development."

This reverts commit 914ce34e5b.

* requires sqlite3 to be installed.

Gemfile

@@ -128,7 +128,6 @@ group :test, :development do
   gem 'pry-nav'
   gem 'byebug', require: ENV['RM_INFO'].nil?
   gem 'rubocop', require: false
-  gem 'mailcatcher', require: false
 end
 
 group :development do

Gemfile.lock

@@ -91,7 +91,6 @@ GEM
     crack (0.4.3)
       safe_yaml (~> 1.0.0)
     crass (1.0.4)
-    daemons (1.2.6)
     danger (5.6.3)
       claide (~> 1.0)
       claide-plugins (>= 0.9.2)
@@ -127,7 +126,6 @@ GEM
       railties (>= 3.1)
     ember-source (2.13.3)
     erubi (1.7.1)
-    eventmachine (1.2.7)
     excon (0.62.0)
     execjs (2.7.0)
     exifr (1.3.4)
@@ -153,9 +151,6 @@ GEM
     globalid (0.4.1)
       activesupport (>= 4.2.0)
     guess_html_encoding (0.0.11)
-    haml (5.0.4)
-      temple (>= 0.8.0)
-      tilt
     hashdiff (0.3.7)
     hashie (3.5.7)
     highline (1.7.10)
@@ -173,7 +168,6 @@ GEM
       rails-dom-testing (>= 1, < 3)
       railties (>= 4.2.0)
       thor (>= 0.14, < 2.0)
-    json (2.1.0)
     jwt (1.5.6)
     kgio (2.11.2)
     kramdown (1.17.0)
@@ -197,16 +191,6 @@ GEM
     lru_redux (1.1.0)
     mail (2.7.1.rc1)
       mini_mime (>= 0.1.1)
-    mailcatcher (0.2.4)
-      eventmachine
-      haml
-      i18n
-      json
-      mail
-      sinatra
-      skinny (>= 0.1.2)
-      sqlite3-ruby
-      thin
     memory_profiler (0.9.10)
     message_bus (2.1.5)
       rack (>= 1.1.3)
@@ -230,7 +214,6 @@ GEM
     multi_xml (0.6.0)
     multipart-post (2.0.0)
     mustache (1.0.5)
-    mustermann (1.0.3)
     nap (1.1.0)
     no_proxy_fix (0.1.2)
     nokogiri (1.8.3)
@@ -419,14 +402,6 @@ GEM
       connection_pool (~> 2.2, >= 2.2.0)
       rack-protection (>= 1.5.0)
       redis (>= 3.3.5, < 5)
-    sinatra (2.0.3)
-      mustermann (~> 1.0)
-      rack (~> 2.0)
-      rack-protection (= 2.0.3)
-      tilt (~> 2.0)
-    skinny (0.2.2)
-      eventmachine (~> 1.0)
-      thin
     slop (3.6.0)
     sprockets (3.7.2)
       concurrent-ruby (~> 1.0)
@@ -435,18 +410,10 @@ GEM
       actionpack (>= 4.0)
       activesupport (>= 4.0)
       sprockets (>= 3.0.0)
-    sqlite3 (1.3.13)
-    sqlite3-ruby (1.3.3)
-      sqlite3 (>= 1.3.3)
     sshkey (1.9.0)
     stackprof (0.2.11)
-    temple (0.8.0)
     terminal-table (1.8.0)
       unicode-display_width (~> 1.1, >= 1.1.1)
-    thin (1.7.2)
-      daemons (~> 1.0, >= 1.0.9)
-      eventmachine (~> 1.0, >= 1.0.4)
-      rack (>= 1, < 3)
     thor (0.19.4)
     thread_safe (0.3.6)
     tilt (2.0.8)
@@ -520,7 +487,6 @@ DEPENDENCIES
   logster
   lru_redux
   mail (= 2.7.1.rc1)
-  mailcatcher
   memory_profiler
   message_bus
   mini_mime