Gphotos-sync

Add the --album option to sync a sinle album.

Update to Python 3.7 and reduce dependency issues (in particular magic library)
Minor fixes to the comparison feature to reduce false duplicates.
New GPS Location extraction feature (Beta) - will scrape Google Photos Website for the missing location information that the API omits - currently only adds this to the SQL index, but will, in future, update the JPGs with this information.

Now indexes and downloads files in shared albums (but only if the album has a title).
Option to change the log logfile name and location
Better test coverage

Now album links are unique names, avoids name clashes in album folders.
Also, albums folders can move to a new path if their dates change.

Bugfixes and code tidy:-
Support a 'downloaded' flag in the DB for media.
Improved tests and logging
Switch to using ThreadPoolExecutor and Futures for parallel downloads
Add a bad IDs YAML file for broken IDs (workaround to Google issue)
Fix support for Raspberry Pi Zero
Added Codacy, code quality checks