Renamed make_lyra_event_list1.py to lyra_event_list.py

Moved LYTAF_PATH variable to be a kwarg in extract_combined_lytaf().
Formed test/ directory to hold testing modules.  test/test_data/ holds test
sqlite databases.  test/test_data_long/ holds longer versions of test sqlite
databases.  May be deleted in future.
Wrote first draft of test_extract_combined_lytaf() as a unit test for
extract_combined_lytaf(). Yet to be tested.
Next commit
extract_combined_lytaf (and test_extract_combined_lytaf) now works!

lyra_event_list.py: fixed bug converted time strings to unix timestamp and
deleted print statements in extract_combined_lytaf.

test_lyra_event_list.py: fixed assert statement in test_extract_combined_lytaf
Output dictionary of extract_combined_lytaf() now has numpy arrays instead
of lists.
Written first draft od find_lyra_event() to locate flares in LYRA data.
Does not work yet though.
Changed extract_combined_lytaf() and its unit test to output a numpy
record array instead of a dictionary
Deleted copy of fin_lyra_events()s erroneously in test_lyra_event_list.py
find_lyra_events() function can now find events simply according to definitions
but cannot recognise flares on the tails of others or start time or end time
affected by instrumental effects.
Changed find_lyra_events so it time input is an array of datetime objects.
Created function extract_lyra_artifacts() in lyra_event_list.py which take in a
timeseries and retuns a copy of that time series with the periods corresponding
to artifacts in the LYRA annotation file removed.  This is preferred to removing
these artifacts explicitly in find_lyra_events().  This function not ready yet
though.
Also created a function _check_datetime() which checks if input is an array of
datetime objects and if not, tries to convert them.  If this is not possible a
TypeError is raised.
Added functionality to extract_lyra_artifacts(), namely that the user doesn't
have to select which artifacts to remove.  If user doesn't do this, all
artifacts are removed.
Added functionality to extract_lyra_artifacts(), namely that user can have
information on what artifacts were found and removed returned by setting
return_artifacts keyword to True.