Normalise access

[groenroos]

Makes sure that every model field has a predictably formatted access object, regardless of whether or how it's defined.

Closes #162.

[codecov]

Codecov Report

Merging #188 (1fd83cb) into master (3e98042) will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #188      +/-   ##
==========================================
+ Coverage   91.39%   91.41%   +0.02%     
==========================================
  Files          35       35              
  Lines        1243     1247       +4     
==========================================
+ Hits         1136     1140       +4     
  Misses        107      107              

Impacted Files	Coverage Δ
lib/Storage.js	82.59% <ø> (ø)
core/loadModel.js	100.00% <100.00%> (ø)

---

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 3e98042...1fd83cb. Read the comment docs.