Error installing error: could not create '/etc/bash_completion.d': Permission denied

I get this issue:

Which seems to indicate that this MUST be installed as root because it is changing files in /etc

Is that necessary?

```
Installing collected packages: s4cmd
Running setup.py install for s4cmd ... error
Complete output from command /Users/x/devel/x.com/venv3.5/bin/python3.5 -u -c "import setuptools, tokenize;__file__='/private/var/folders/dw/60dbyvqd7v92pkm_515486x00000gw/T/pip-build-c3aqofg5/s4cmd/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /var/folders/dw/60dbyvqd7v92pkm_515486x00000gw/T/pip-_my13cw8-record/install-record.txt --single-version-externally-managed --compile --install-headers /Users/x/devel/x.com/venv3.5/include/site/python3.5/s4cmd:
running install
running build
running build_py
creating build
creating build/lib
copying s4cmd.py -> build/lib
running build_scripts
creating build/scripts-3.5
copying s4cmd -> build/scripts-3.5
copying and adjusting s4cmd.py -> build/scripts-3.5
changing mode of build/scripts-3.5/s4cmd.py from 644 to 755
running install_lib
running install_data
creating /etc/bash_completion.d
error: could not create '/etc/bash_completion.d': Permission denied

----------------------------------------
Command "/Users/x/devel/x.com/venv3.5/bin/python3.5 -u -c "import setuptools, tokenize;__file__='/private/var/folders/dw/60dbyvqd7v92pkm_515486x00000gw/T/pip-build-c3aqofg5/s4cmd/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /var/folders/dw/60dbyvqd7v92pkm_515486x00000gw/T/pip-_my13cw8-record/install-record.txt --single-version-externally-managed --compile --install-headers /Users/x/devel/x.com/venv3.5/include/site/python3.5/s4cmd" failed with error code 1 in /private/var/folders/dw/60dbyvqd7v92pkm_515486x00000gw/T/pip-build-c3aqofg5/s4cmd/
```

Start with setup.py and the installation output's bash-completion destination, /etc/bash_completion.d. Check why installation attempts to create that system directory and determine whether a non-root installation can complete without writing there. Done means the package installs successfully without requiring root, with bash completion behavior addressed.

Written by the indexing model from the issue text.