Added excellon support and refactored project
added ExcellonFile class
added doc folder
Add CNC base classes and settings class
Add travis.yml
add .travis.yml
fix .travis.yml
doc update
add coveralls
Fix coveralls
doc update
tests update
tests
added numpydoc
add excellon statements
Fix import error
Update excellon statements/ExcellonFile
add excellon file write
add tests
add tests