Adding license file and removed git dependency from gemspec file

LICENSE.md

@@ -0,0 +1,13 @@
+Copyright 2016 Active Agent AG
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+		http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.

logstash-codec-thrift.gemspec

@@ -11,7 +11,7 @@ Gem::Specification.new do |s|
   s.require_paths   = ["lib"]
 
   # Files
-  s.files = `git ls-files`.split($\)
+  s.files = Dir['lib/**/*','*.gemspec','*.md','Gemfile']
 
   # Tests
   s.test_files = s.files.grep(%r{^(test|spec|features)/})
@@ -25,5 +25,4 @@ Gem::Specification.new do |s|
 
   s.add_development_dependency 'logstash-devutils', '>= 0.0.15'
 
-
 end