100% test coverage again + handling of test warnings

[caronc]

• Some testing reworked to handle all warnings thrown during them.
• Some warnings will still be thrown if your version of Click is less than v7.0 (fixed here - commit):

test/test_cli.py::test_apprise_cli
  /usr/lib64/python3.7/os.py:678: ResourceWarning: unclosed <socket.socket fd=8, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('127.0.0.1', 54516)>
    raise KeyError(key) from None
  /usr/lib64/python3.7/os.py:678: ResourceWarning: unclosed <socket.socket fd=10, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('127.0.0.1', 54518)>
    raise KeyError(key) from None
  /usr/lib64/python3.7/os.py:678: ResourceWarning: unclosed <socket.socket fd=11, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('127.0.0.1', 54520)>
    raise KeyError(key) from None
  /usr/lib/python3.7/site-packages/click/core.py:847: ResourceWarning: unclosed <socket.socket fd=8, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('127.0.0.1', 54522)>
    all_names.difference_update(param.opts)
  /usr/lib/python3.7/site-packages/click/core.py:847: ResourceWarning: unclosed <socket.socket fd=10, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('127.0.0.1', 54524)>
    all_names.difference_update(param.opts)

• Testing coverage back to 100%
• Additional tests added to handle other edge cases associated with URLs