I did an install of piecash with:

pip install -U piecash[pandas,mysql]

and now if I try to do an open_book with a mysql uri, I am getting

"ModuleNotFoundError: No module named 'MySQLdb'"

I tried doing a pip install mysqlclient but it fails:

`
pip install mysqlclient
Collecting mysqlclient
Using cached mysqlclient-2.1.0.tar.gz (87 kB)
Preparing metadata (setup.py) ... error
error: subprocess-exited-with-error

� python setup.py egg_info did not run successfully.
� exit code: 1
��> [16 lines of output]
/bin/sh: mysql_config: command not found
/bin/sh: mariadb_config: command not found
/bin/sh: mysql_config: command not found
Traceback (most recent call last):
File "", line 36, in
File "", line 34, in
File "/private/var/folders/y2/38gkkc0s7d52_mr_s6zfj7m80000gq/T/pip-install-jhyhz4q5/mysqlclient_7d815c9d48da443fb56a51023ad822bf/setup.py", line 15, in
metadata, options = get_config()
File "/private/var/folders/y2/38gkkc0s7d52_mr_s6zfj7m80000gq/T/pip-install-jhyhz4q5/mysqlclient_7d815c9d48da443fb56a51023ad822bf/setup_posix.py", line 70, in get_config
libs = mysql_config("libs")
File "/private/var/folders/y2/38gkkc0s7d52_mr_s6zfj7m80000gq/T/pip-install-jhyhz4q5/mysqlclient_7d815c9d48da443fb56a51023ad822bf/setup_posix.py", line 31, in mysql_config
raise OSError("{} not found".format(_mysql_config_path))
OSError: mysql_config not found
mysql_config --version
mariadb_config --version
mysql_config --libs
[end of output]

note: This error originates from a subprocess, and is likely not a problem with pip.
error: metadata-generation-failed

� Encountered error while generating package metadata.
��> See above for output.

note: This is an issue with the package mentioned above, not pip.
hint: See above for details.
`