More Ruby 1.9 fixes (#37)

* Pin terminal-ansicolor to 1.3.0

* Pin mime-types to <3

* Pin rest-client to <2

* Pin tins to 1.6.0

Gemfile

@@ -1,4 +1,5 @@
 source 'https://rubygems.org/'
+
 gemspec
 
 group :development do
@@ -8,7 +9,11 @@ group :development do
 
   gem 'coveralls', :require => false
 
-  platform :ruby_18, :ruby_19 do
+  platform :ruby_19 do
+    gem 'mime-types', '>= 2.0', '< 3.0'
+    gem 'rest-client', '>= 1.0', '< 2.0'
     gem 'simplecov', '>= 0.10', '< 0.12'
+    gem 'term-ansicolor', '1.3.2'
+    gem 'tins', '1.6.0'
   end
 end