Lots of progress

[Mikea1985]

I fixed up precalc, so that it can now handle being given a long list of observations, figure out which observations compose a tracklet, parse them and calculate the location of observer etc. As far as I can tell, all the functions work as expected except save_tracklets; the sql complains something about "OperationalError: no such table: tracklets"

Other changes:

• I added a couple of notebooks demoing that I made while testing. May be useful.
• Changed imports of sifter modules to use relative imports; more pythonic and nicer looking.
• Added a fake tracklet of a known object to the test.itf file, to test that something known to be in there definitely gets found
• Updated test_tracklets.py to test the current functionality
• Made test_tracklets.py mostly PEP8 compatible
• Implemented PyTest for test_tracklets.py
• added a setup.py file, just because why not.

[matthewjohnpayne]

Questions / Comments (1) Thanks for all of your work to whip this into shape (2) The setup.py points to trippy, so that should be updated (3) How are you getting the test_tracklets.py to work: are you already installing sifter as a package at that point? When I attempt to run test_tracklets.py, I get messages to the effect that ...

ImportError while importing test module '/Users/matthewjohnpayne/Envs/sifter/tests/test_tracklets.py'. Hint: make sure your test modules/packages have valid Python names. Traceback: tests/test_tracklets.py:26: in from sifter import precalc, sql E ModuleNotFoundError: No module named 'sifter'