Treat Gemfile and .gemspecs as Ruby (prontolabs#344)

* Treat Gemfile and .gemspecs as Ruby

* Fix path of Gemfile

lib/pronto/runner.rb

@@ -28,7 +28,10 @@ def ruby_patches
     end
 
     def ruby_file?(path)
-      rb_file?(path) || rake_file?(path) || ruby_executable?(path)
+      rb_file?(path) ||
+        rake_file?(path) ||
+        gem_file?(path) ||
+        ruby_executable?(path)
     end
 
     def repo_path
@@ -45,6 +48,10 @@ def rake_file?(path)
       File.extname(path) == '.rake'
     end
 
+    def gem_file?(path)
+      File.basename(path) == 'Gemfile' || File.extname(path) == '.gemspec'
+    end
+
     def ruby_executable?(path)
       return false if File.directory?(path)
       line = File.open(path, &:readline)

spec/pronto/runner_spec.rb

@@ -26,6 +26,21 @@ module Pronto
         it { should be_truthy }
       end
 
+      context 'ending with .gemspec' do
+        let(:path) { 'test.gemspec' }
+        it { should be_truthy }
+      end
+
+      context 'named Gemfile' do
+        let(:path) { 'Gemfile' }
+        it { should be_truthy }
+      end
+
+      context 'named Gemfile in directory' do
+        let(:path) { 'test/Gemfile' }
+        it { should be_truthy }
+      end
+
       context 'executable' do
         let(:path) { 'test' }
         before { File.stub(:open).with(path).and_return(shebang) }