Remove backports from dependencies

... not used.

Gemfile

@@ -2,8 +2,6 @@ source 'https://rubygems.org'
 
 gemspec
 
-gem 'backports', :platform => :ruby_18
-
 group :development do
   gem 'guard'
   gem 'guard-bundler'

Gemfile.lock

@@ -7,18 +7,17 @@ PATH
 GEM
   remote: https://rubygems.org/
   specs:
-    backports (2.6.5)
     coderay (1.0.8)
     diff-lcs (1.1.3)
-    guard (1.5.4)
-      listen (>= 0.4.2)
+    guard (1.6.0)
+      listen (>= 0.6.0)
       lumberjack (>= 1.0.2)
       pry (>= 0.9.10)
       thor (>= 0.14.6)
     guard-bundler (1.0.0)
       bundler (~> 1.0)
       guard (~> 1.1)
-    guard-rspec (2.3.1)
+    guard-rspec (2.3.3)
       guard (>= 1.1)
       rspec (~> 2.11)
     kramdown (0.14.1)
@@ -44,7 +43,7 @@ GEM
     rspec-core (2.12.2)
     rspec-expectations (2.12.1)
       diff-lcs (~> 1.1.3)
-    rspec-mocks (2.12.0)
+    rspec-mocks (2.12.1)
     simplecov (0.7.1)
       multi_json (~> 1.0)
       simplecov-html (~> 0.7.1)
@@ -60,7 +59,6 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
-  backports
   guard
   guard-bundler
   guard-rspec

lib/zero.rb

@@ -1,6 +1,3 @@
-if RUBY_VERSION <= '1.9'
-  require 'backports'
-end
 require 'zero/patches/uri'
 
 module Zero