Use pip instead of apt-get for python package dependencies

[elcojacobs]

The python packages on apt are often very outdated, we should not rely on it.
The latest version is also different for various operating systems. (Linux flavors or Windows).

It would be better to install the packages from pip. The installer and upgrade script should be modified for this.

Related issue (demonstrates the problem with psutil):
BrewPi/brewpi-script#47

[vanosg]

It looks like you beat me to this- are you good with closing, or is there more to do?

[vanosg]

Also, to be fair, stating 'apt is outdated' isn't necessarily fair or accurate. Maintainers take a while to update the repository with binaries based on stable builds (usually). So while its not cutting edge, there is hopefully less chance of buggy, bleeding-edge code being placed into a repo. Just be aware that the pip repos being updated faster means (generally) less testing has gone into it before it was fielded.

Additionally, something to keep in mind throughout this whole process is that when a user updates and a python lib is updated with something new like name(), the rest of their code will break!