Merge pull request #10 from FranciscoCanas/master

Updating project url in setup file, code cleanup, additional dependency tests.
Refactored dependencies into a class and added short-circuiting for condition
dependencies that have already been verified to be broken.
Added shot-circuiting for well-defined conditions that have already been
verified.
Added better short-circuiting on well-defined conditions: a cond's tree should
only need to be traversed one time now.
Added the fail_on_undefined_vars flag to 'exists' conditions.
Changed 'bad condition' msg to 'ill-defined condition'
Tiny edits to display_paths in reporter class.
Added a bit of formatting to the Reporter class and made display_paths a
Reporter method.
Added support for XOR conditions to dependency grapher.
PEP8 formatting edits.
Refactored dependency verification test
Merge branch 'FranciscoCanas-dep_path_shortcircuit'
Merge pull request #12 from FranciscoCanas/dep_path_shortcircuit

Dependency Tests Refactoring
Merge pull request #13 from ahmedlawi92/master

Edits to dependency verification pull request
Release 0.0.3.5 changes
Merge pull request #14 from ahmedlawi92/master

Release 0.0.3.5 changes
Added pip requirements file to project.
Merge pull request #16 from FranciscoCanas/requirements

Added pip requirements file to project.
Added BUILD results badge to README markdown.
Removed unicode from reporter output.