Add colors to cli messages

[Zebralt]

Related issue: #5

Here's what this PR brings:

• when an action is successful, print in green (Killed X, Scheduled X);
• when an exception is raised, print in red + hide traceback for commonplace errors (file not found, unsupported platform, hickory specific errors);
• the output of status isn't colored because as a table-like output, it's likely to be passed through a pipe for other purposes (although you could always detect when this happens using os.isatty and not add any colors).
• added hickory/__main__.py to be able to run the package against a specific python runtime: python -m hickory targeting the folder or the installed package.

Coloring is done using colorama, a popular terminal coloring package. It also brings cross-compatibility with Windows since coloring is done through API calls rather than escape sequences in there.

[maxhumber]

Zebralt! Thanks for your contribution.

Unfortunately, hickory has an aversion to and does not want take on any third party dependencies (that's my bad, I should have made this clear in the issue)

Do you think we could rewrite the the colouring functions with something like this: https://stackoverflow.com/a/58149095/3731467?

Otherwise, the rest of the code fixes you've added are solid 👍

[Zebralt]

Yeah, I can do that. I'll just replace the colorama imports with custom ones.

If you ever want to bring colors to Windows though, colorama is probably your best bet since there's a whole part of the package that is dedicated to translate escape sequences into Windows calls. Not that I'm a Windows fanboy or anything of the like :P

[Zebralt]

@maxhumber
Hi, could you review my last changes ?
The main implementation is in colors.py.