Omar changes

See merge request !24

# Conflicts:
#   AmpScan/ampVis.py
#   GUIs/AmpScanGUI.py

Merge in Jack's changes

Closes #45 and #43

See merge request !23

Fixed #45

Now just exits safely when no file is selected by file manager

Adding Error message for registering which occurs when less than 2 objects loaded

temporarily reverted to using manual tests while pytest is not installed

Currently GUI docs are not working, but I'll wait until we manage branches to fix them.

Added validation to both flip and rotMatrix.

Added checks for incorrect dimensions in rotate method of AmpObject.
Added automatic casting to np array if a list or tuple is passed in.
Added tests for these new functions