Fix dependencies for Ruby 1.8 compatibility

Author: SFEley

bin/git-tail

@@ -1,6 +1,7 @@
 #!/usr/bin/env ruby
 lib_dir = File.expand_path('../../lib', __FILE__)
 $LOAD_PATH.unshift(lib_dir) unless $LOAD_PATH.include?(lib_dir)
+require 'rubygems'
 require 'trollop'
 require 'git/tail'
 

git-tail.gemspec

@@ -31,6 +31,6 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "rake"
 
   spec.add_runtime_dependency "trollop", "~> 2.0"
-  spec.add_runtime_dependency "rainbow", "~> 2.0"
+  spec.add_runtime_dependency "rainbow", "~> 1.99"
   spec.add_runtime_dependency "childprocess", "~> 0.5.2"
 end