Added Pptx support
Added support for Ppt
Updated the README a bit
Updated the README a bit more
Updated the README a bit more
Added initial Travis CI configuration
Added support for Xlsx files
Abstracted some things out to the File class
Added Presentation format and updated Pptx class
Updated .travis.yml with the correct ExifTool package name
Updated .travis.yml with ExifTool dependencies
Updated README with Travis CI build status
Updated composer.lock