refactor: Improve the way settings are used

[mariusmucenicu]

• Use production settings directly as though it were created instead of deriving it from default_settings
• Use the default_settings directly in tests (instead of building it's path)

Resolves #165

[codecov[bot]]

Codecov Report

Merging #166 into master will decrease coverage by 0.03%. The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #166      +/-   ##
==========================================
- Coverage   76.08%   76.04%   -0.04%     
==========================================
  Files          11       11              
  Lines        1242     1240       -2     
==========================================
- Hits          945      943       -2     
  Misses        297      297

Impacted Files	Coverage Δ
knowlift/__init__.py	100% <ø> (ø)	:arrow_up:
wsgi.py	38.24% <100%> (ø)	:arrow_up:
tests/test_web.py	100% <100%> (ø)	:arrow_up:

---

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 6ead801...e5b2bad. Read the comment docs.