Matrix capability integration

To support Matrix as an outlet for ghi we:
-edited ghi/configuration.py to read, check and use the (optional) Matrix-settings from the .yml
-created ghi/ghimatrix.py to facilitate creating credential-files, logging onto a Matrix server and sending messages to one or more rooms on it by using the matrix-nio module
-changed some naming and matrix-specific things in most of the files
-changed the README.md en .ghy.yml.example to include the new Matrix-support
-created ghi/util.py to facilitate in a workaround for a Matrix-issue (matrix-org/matrix-appservice-irc#1562)
-added relevant exception-handlers

No changes to the config-file are necessary when using IRC.

It works quite well with server.py, haven't tested it with AWS though, but should work as well.

Closes #27

Co-authored-by: W. J. van der Laan <laanwj@protonmail.com>

improved exception handling for unexpected and malformed messages

Version 0.1.3

Properly handle IRC Authentication failures

Log version when debug enabled