use of `scripts` in setup.py causes errors with virtualenvs

[cs01]

When running mssql-cli from within an activated virtualenv, everything is fine because the virtual env's python is the first match on the PATH. However, when invoking mssql-cli from myvenv/bin/mssql-cli while the virtual environment is not activated, we get

> myvenv/bin/mssql-cli
/usr/bin/python: Error while finding module specification for 'mssqlcli.main' (ModuleNotFoundError: No module named 'mssqlcli')

as noted in pypa/pipx#12.

This is because the script mssql-cli is custom made and hardcoded to invoke a new bash shell, ignoring any virtual environment.

There are a few solutions. The first is easiest and most common.

1. Use the standard entry_points entry instead of scripts

    entry_points = {"console_scripts": [
        "mssql-cli.bat = mssqlcli.main:main",
        "mssql-cli = mssqlcli.main:main"
        ]},

2. Leave as a script, but use python instead of bash; make the interpreter /usr/bin/env python instead of bash, similar to how awscli does it: https://github.com/aws/aws-cli/blob/develop/bin/aws
3. In the script mssql-cli test if there is an activate script present, and if so, run source activate before running python -m mssqlcli.main "$@". This is hacky and I would not go this route.

[MrMeemus]

@cs01 thanks for being so proactive with this issue! The only concern I had is if we are not referencing the scripts any more we lose the IO Encoding. This would affect us when we support pipeable output, which we can revisit when we cross that bridge.

One question I do have, what is the expected behavior if running with multiple virtual environments that are not activated? or the case when another virtual environment is activated that did not install mssql-cli?

I'll go ahead and merge your change. Thanks again!

[cs01]

I just realized the two scripts that are no longer used should be deleted as well. I didn't do that in the PR.

[cs01]

One question I do have, what is the expected behavior if running with multiple virtual environments that are not activated?

Sorry, I never responded to this. If a virtual environment is not activated, then these entry points are not available on your $PATH.

or the case when another virtual environment is activated that did not install mssql-cli?

If this is the case, then the entry points are also not available on your $PATH.