Add resize to Renderable.js

[akaszynski]

Automatically resizes the pythreejs Renderer.

Resolves #362.

[codecov-commenter]

Codecov Report

Merging #374 (671f610) into master (a78cb57) will increase coverage by 0.10%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #374      +/-   ##
==========================================
+ Coverage   70.86%   70.96%   +0.10%     
==========================================
  Files          23       23              
  Lines         834      837       +3     
==========================================
+ Hits          591      594       +3     
  Misses        243      243              

Impacted Files	Coverage Δ
pythreejs/_base/renderable.py	85.96% <100.00%> (+0.25%)	:arrow_up:
pythreejs/core/Renderer.py	82.97% <100.00%> (+0.37%)	:arrow_up:
pythreejs/renderers/WebGLRenderer.py	100.00% <100.00%> (ø)

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[akaszynski]

Hi @vidartf,

This is ready for review.

This repo has been a bit light as of late in regards to commits and PR merges. I'm at a point that I'd like to take up maintenance of this repo if possible.