Refactoring image cropping
refactoring image cropping
Refactoring straighten.py -> DiagramAnalyzer
Restructuring file scheme
Merge branch 'master' of https://github.com/dinopants174/SmarterBoard into sarah
Merge pull request #13 from dinopants174/sarah

Sarah
Merge branch 'master' of https://github.com/dinopants174/SmarterBoard into Ryan
Removed all use cases of cv2. Updated predict method to first convert PIL images to ndarrays.  Added docstrings for Preprocessing class to explicitly ask for ndarray images as inputs
entire pipeline written. untested.