Library editing updates

[blacktwin]

Description

Adding convenience methods to add and remove location(s) (paths) to a library. Updating library add() method to allow for muliple locations on creation of library.

Fixes or addresses #827

Example

plex = PlexServer(PLEX_URL, PLEX_TOKEN, session=sess)

locations = ["D:\\plexlibraries\\shows",
             "D:\\plexlibraries\\shows_optimized"]

plex.library.add(name='Test Library', type='show', agent='tv.plex.agents.series',
                      scanner='Plex TV Series', location=locations, language='U')
					  
testLibrary = plex.library.section('Test Library')
testLibrary.removeLocations(locations[0])
testLibrary.addLocations(locations[0])

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated the docstring for new or existing methods
• I have added tests when applicable

[blacktwin]

TODO: Add tests

[blacktwin]

Still needs tests.

• Create library with multiple paths with an invalid path
• Create library with multiple paths with valid paths
• Add path(s) to test library with valid paths
• Add path(s) to test library with an invalid path
• Remove path(s) to test library with valid paths
• Remove path(s) to test library with an invalid path

[JonnyWong16]

Few more tests:

• BadRequest when trying to remove all locations.
• edit directly with kwargs['location'].
• addLocations with a Path object.
• removeLocations with a Path object.
• isBrowsable with a Path object.

[blacktwin]

I don't think we should include Path object for adding or removing locations. plex.browse('path/to/stuff') returns a list of the Path objects from in the queried path but not the Path object for the queried path. This will either fail if the queried path does not have any subfolder or would result in adding each subfolder instead of the queried path when using .addLocation(Path).