* use `choices` attribute from parser.add_argument() instead of complex actions override
* use metavar to improve --help output
* use custom 'range_type' for length argument
* test _calc_entropy()
* test _get_configured_rules()
* test _get_set_of_characters()
* test _consume_entropy()
* test _get_one_char_per_rule()
* test _insert_string_pseudo_randomly()
* test _render_password()
create a cli with python.
python will be installed by default on a lot of system.
* use getpass python native module
Fixes: https://github.com/lesspass/lesspass/issues/305
* use lesspass python code generator from Maurits van der Schee
Fixes: https://github.com/lesspass/lesspass/issues/328
tested with python2.7 and python3.6
breaking changes:
* -c is associated with --copy flag to copy the password
* -C is associated with the counter (previously -c)