Pin actionmailer to ~> 4.2.9 and update railties

**Why**: To allow bummr to update gems. Otherwise, it will try to
upgrade to 5.x, which is incompatible with some of the other gems that
are pinned to certain versions.

Gemfile

@@ -1,7 +1,7 @@
 source 'https://rubygems.org'
 
 ruby '2.3.3'
-gem 'actionmailer'
+gem 'actionmailer', '~> 4.2.9'
 gem 'compass-rails'
 gem 'dalli', '~> 2.7.1'
 gem 'faraday-http-cache', '~> 1.0'

Gemfile.lock

@@ -1,29 +1,29 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    actionmailer (4.2.8)
-      actionpack (= 4.2.8)
-      actionview (= 4.2.8)
-      activejob (= 4.2.8)
+    actionmailer (4.2.9)
+      actionpack (= 4.2.9)
+      actionview (= 4.2.9)
+      activejob (= 4.2.9)
       mail (~> 2.5, >= 2.5.4)
       rails-dom-testing (~> 1.0, >= 1.0.5)
-    actionpack (4.2.8)
-      actionview (= 4.2.8)
-      activesupport (= 4.2.8)
+    actionpack (4.2.9)
+      actionview (= 4.2.9)
+      activesupport (= 4.2.9)
       rack (~> 1.6)
       rack-test (~> 0.6.2)
       rails-dom-testing (~> 1.0, >= 1.0.5)
       rails-html-sanitizer (~> 1.0, >= 1.0.2)
-    actionview (4.2.8)
-      activesupport (= 4.2.8)
+    actionview (4.2.9)
+      activesupport (= 4.2.9)
       builder (~> 3.1)
       erubis (~> 2.7.0)
       rails-dom-testing (~> 1.0, >= 1.0.5)
       rails-html-sanitizer (~> 1.0, >= 1.0.3)
-    activejob (4.2.8)
-      activesupport (= 4.2.8)
+    activejob (4.2.9)
+      activesupport (= 4.2.9)
       globalid (>= 0.3.0)
-    activesupport (4.2.8)
+    activesupport (4.2.9)
       i18n (~> 0.7)
       minitest (~> 5.1)
       thread_safe (~> 0.3, >= 0.3.4)
@@ -83,6 +83,7 @@ GEM
       tins (~> 1.6)
     crack (0.4.3)
       safe_yaml (~> 1.0.0)
+    crass (1.0.2)
     dalli (2.7.6)
     debug_inspector (0.0.2)
     declarative (0.0.9)
@@ -163,7 +164,7 @@ GEM
     htmlentities (4.3.4)
     httpclient (2.8.3)
     hurley (0.2)
-    i18n (0.8.5)
+    i18n (0.8.6)
     ice_nine (0.11.2)
     json (2.1.0)
     jwt (1.5.6)
@@ -184,7 +185,8 @@ GEM
     logging (2.2.0)
       little-plugger (~> 1.1)
       multi_json (~> 1.10)
-    loofah (2.0.3)
+    loofah (2.1.1)
+      crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     mail (2.6.6)
       mime-types (>= 1.16, < 4)
@@ -194,12 +196,12 @@ GEM
     mime-types (3.1)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2016.0521)
-    mini_portile2 (2.2.0)
-    minitest (5.10.2)
+    mini_portile2 (2.3.0)
+    minitest (5.10.3)
     multi_json (1.12.1)
     multipart-post (2.0.0)
-    nokogiri (1.8.0)
-      mini_portile2 (~> 2.2.0)
+    nokogiri (1.8.1)
+      mini_portile2 (~> 2.3.0)
     ohanakapa (1.1.2)
       sawyer (~> 0.5.3)
     os (0.9.6)
@@ -234,9 +236,9 @@ GEM
       rails_stdout_logging
     rails_serve_static_assets (0.0.5)
     rails_stdout_logging (0.0.4)
-    railties (4.2.8)
-      actionpack (= 4.2.8)
-      activesupport (= 4.2.8)
+    railties (4.2.9)
+      actionpack (= 4.2.9)
+      activesupport (= 4.2.9)
       rake (>= 0.8.7)
       thor (>= 0.18.1, < 2.0)
     rainbow (2.2.2)
@@ -356,7 +358,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
-  actionmailer
+  actionmailer (~> 4.2.9)
   better_errors
   binding_of_caller (~> 0.7.2)
   bummr