slim down the GEM [skip ci]

Author: wied03

react-opal.gemspec

@@ -11,9 +11,7 @@ Gem::Specification.new do |s|
   s.license      = 'MIT'
   s.description  = "Write reactive UI component with Ruby's elegancy and compiled to run in Javascript."
 
-  s.files          = `git ls-files`.split("\n")
-  s.executables    = `git ls-files -- bin/*`.split("\n").map { |f| File.basename(f) }
-  s.test_files     = `git ls-files -- {test,spec,features}/*`.split("\n")
+  s.files          = Dir.glob('lib/**/*.rb') + Dir.glob('opal/**/*.rb')
   s.require_paths  = %w(lib)
 
   s.add_runtime_dependency 'opal', '>= 0.8.0'