FIX: update mail gem to fix UTF-8 parsing issue

Gemfile

@@ -24,7 +24,7 @@ else
   gem 'seed-fu'
 end
 
-gem 'mail', require: false
+gem 'mail', '2.7.1.rc1', require: false
 gem 'mini_mime'
 gem 'mini_suffix'
 

Gemfile.lock

@@ -161,14 +161,14 @@ GEM
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     lru_redux (1.1.0)
-    mail (2.7.0)
+    mail (2.7.1.rc1)
       mini_mime (>= 0.1.1)
     memory_profiler (0.9.10)
     message_bus (2.1.4)
       rack (>= 1.1.3)
     metaclass (0.0.4)
     method_source (0.8.2)
-    mini_mime (0.1.3)
+    mini_mime (1.0.0)
     mini_portile2 (2.3.0)
     mini_racer (0.1.15)
       libv8 (~> 6.3)
@@ -436,7 +436,7 @@ DEPENDENCIES
   logstash-logger
   logster
   lru_redux
-  mail
+  mail (= 2.7.1.rc1)
   memory_profiler
   message_bus
   mini_mime

spec/components/email/receiver_spec.rb

@@ -183,7 +183,7 @@ describe Email::Receiver do
 
     it "works" do
       expect { process(:text_reply) }.to change { topic.posts.count }
-      expect(topic.posts.last.raw).to eq("This is a text reply :)")
+      expect(topic.posts.last.raw).to eq("This is a text reply :)\n\nEmail parsing should not break because of a UTF-8 character: ’")
       expect(topic.posts.last.via_email).to eq(true)
       expect(topic.posts.last.cooked).not_to match(/<br/)
 
@@ -233,7 +233,7 @@ describe Email::Receiver do
     it "uses text when prefer_html site setting is enabled but no html is available" do
       SiteSetting.incoming_email_prefer_html = true
       expect { process(:text_reply) }.to change { topic.posts.count }
-      expect(topic.posts.last.raw).to eq("This is a text reply :)")
+      expect(topic.posts.last.raw).to eq("This is a text reply :)\n\nEmail parsing should not break because of a UTF-8 character: ’")
     end
 
     it "removes the 'on <date>, <contact> wrote' quoting line" do