Avoid having content-length warning in dev log.

Gemfile

@@ -58,4 +58,7 @@ group :development do
 
   # Hide assets requests in log
   gem 'quiet_assets'
+
+  # Avoid having content-length warnings
+  gem 'thin'
 end

Gemfile.lock

@@ -72,6 +72,7 @@ GEM
     commonjs (0.2.6)
     daemons (1.1.9)
     erubis (2.7.0)
+    eventmachine (1.0.3)
     exception_notification (2.6.1)
       actionmailer (>= 3.0.4)
     execjs (1.4.0)
@@ -192,6 +193,10 @@ GEM
     test-unit (2.5.3)
     therubyracer (0.10.2)
       libv8 (~> 3.3.10)
+    thin (1.5.1)
+      daemons (>= 1.0.9)
+      eventmachine (>= 0.12.6)
+      rack (>= 1.0.0)
     thor (0.17.0)
     tilt (1.3.6)
     treetop (1.4.12)
@@ -250,6 +255,7 @@ DEPENDENCIES
   sqlite3
   test-unit
   therubyracer
+  thin
   twitter-bootstrap-rails
   uglifier (>= 1.0.3)
   whenever