Augmented feature generation testing (which currently tests all features
against previously-computed values) with unit tests for specific
algorithms. Where possible the tests compare to a priori closed form
solutions; in a few cases where this isn't practical, we compare to the
current outputof that function (so these tests are only beneficial
going forward).

Move relevant code from TCP library into new path; leave TCP code in
place for now, but nothing there should be used anywhere at this point.

Remove unnecessary code from lc_tools module that is not used for
feature generation; use dask for computing feature values, in the same
way as is now done for science_features.

Naming conventions and implementation details were inconsistent between
`lc_tools` (now `obs_feature_tools`), `science_feature_tools`, and in
various other places throughout the featurization pipeline. Improves
consistency within these areas and removes some deprecated/unnecessary
logic, including 1) featurization of a single time series now always
returns a dict, instead of sometimes a list containing a single dict;
2) `short_fname` keys into dictionaries are now always the filename
without the extension (previously the extension was included in some
places and not others).

Undo test_prediction_page sleep change

This reverts commit 0120754.
For now, restore TCP module to simplify the refactor pull request. Will
remove TCP later after the replacement code has been merged.

Tidying up: remove import of deprecated `lc_tools`, add a couple tests
for `obs_feature_tools`, change some test data, remove extraneous
comments, add a couple of docstrings, change `test_flask_app` database
teardown procedure.