Make installation process more robust for users

[qwhelan]

Given our lack of wheels, installation is more complex than some other projects. Attempt to improve the user experience in a few ways:

• Add dedicated installation page in documentation
• Do a test compile to see if a compiler and/or Python development libraries are even available, and point users to installation page if not.
• Add explicit Docker-based tests for minimum installation dependencies for a few OSes
• Specify the C standard used when compiling under gcc=4.8 or lower, which is the default on RHEL/CentOS 7

cc #281

[codecov-io]

Codecov Report

Merging #337 into master will decrease coverage by 0.23%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master     #337      +/-   ##
==========================================
- Coverage   85.32%   85.09%   -0.24%     
==========================================
  Files          29       29              
  Lines        3899     3911      +12     
  Branches      287      290       +3     
==========================================
+ Hits         3327     3328       +1     
- Misses        529      540      +11     
  Partials       43       43

Impacted Files	Coverage Δ
bottleneck/src/bn_config.py	0% <0%> (ø)	⬆️
bottleneck/src/move_template.c	93.02% <0%> (+0.21%)	⬆️

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