changed open to File.open to prevent namespace issue

if the local file used is created using Tempfile.new and is included into a rails app. method open fails because of  a namespace naming conflict in ruby kernel & rails. using File.open will prevent this from happening
changed open to File.open to prevent namespace issue

if the local file used is created using Tempfile.new and is included into a rails app. method open fails because of  a namespace naming conflict in ruby kernel & rails. using File.open will prevent this from happening
Merge pull request #4 from freibuis/master

changed open to File.open to prevent namespace issue