Simplify gem build

* Remove sass-rails.gemspec.erb
* There are no executables

To build the gem, just run `rake build`

Author: teeparham

Rakefile

@@ -12,17 +12,3 @@ end
 
 desc 'Default: run unit tests.'
 task default: :test
-
-specname = "sass-rails.gemspec"
-deps = `git ls-files`.split("\n") - [specname]
-
-file specname => deps do
-  files       = `git ls-files`.split("\n")
-  executables = `git ls-files -- bin/*`.split("\n").map{ |f| File.basename(f) }
-
-  require 'erb'
-
-  File.open specname, 'w:utf-8' do |f|
-    f.write ERB.new(File.read("#{specname}.erb")).result(binding)
-  end
-end