Error on invocation: "No module named mssqlcli"

Hello, I am on macOS Catalina 10.15.7, trying to use mssql-cli to query a SQL Server DB, I installed using `pip3 install mssql-cli`, but for some reason the CLI thinks it should be pointed at Python 2.7:

```sh
❯ pip3 install mssql-cli
< ... >
❯ mssql-cli
/System/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python: No module named mssqlcli
```

for reference here is the version info of my various relevant commands:

```sh
❯ which pip3
/Library/Frameworks/Python.framework/Versions/3.8/bin/pip3
❯ pip3 --version
pip 21.1.3 from /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/pip (python 3.8)
❯ which python3
/Library/Frameworks/Python.framework/Versions/3.8/bin/python3
❯ python3 --version
Python 3.8.2
❯ which pip
/Library/Frameworks/Python.framework/Versions/3.8/bin/pip
❯ pip --version
pip 21.1.3 from /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/pip (python 3.8)
❯ which python
/usr/bin/python
❯ python --version
Python 2.7.16
```

Any pointers for un-crossing the wires to point at the correct directory on cli startup would be appreciated.

Reproduzieren Sie den Fehler anhand der angegebenen Python-3.8- und Python-2.7-Pfade, beginnend am Einstiegspunkt des installierten mssql-cli-Befehls. Vergleichen Sie, wie der Befehl mssqlcli mit dem von pip3 verwendeten Interpreter auflöst, und überprüfen Sie anschließend, dass mssql-cli das installierte Python-3-Paket verwendet und keinen Modulfehler mehr auslöst.

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