WIP: Python language support

[jkloetzke]

This is the first draft to support Python as scripting language. Some parts are still missing and it's almost untested...

[codecov[bot]]

Codecov Report

Merging #423 (1920662) into master (6288112) will decrease coverage by 0.22%. The diff coverage is 70.37%.

@@            Coverage Diff             @@
##           master     #423      +/-   ##
==========================================
- Coverage   82.46%   82.24%   -0.23%     
==========================================
  Files          42       42              
  Lines       13569    13652      +83     
==========================================
+ Hits        11190    11228      +38     
- Misses       2379     2424      +45     

Impacted Files	Coverage Δ
pym/bob/languages.py	82.70% <59.37%> (-7.97%)	:arrow_down:
pym/bob/input.py	90.45% <96.77%> (+0.04%)	:arrow_up:
pym/bob/invoker.py	82.39% <100.00%> (+0.30%)	:arrow_up:
pym/bob/utils.py	82.82% <0.00%> (-1.44%)	:arrow_down:

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 6288112...1920662. Read the comment docs.