Make test_all configurable with flags

[tkf]

Commit Message

Make test_all configurable with flags (#35)

There are a lot of repetition across packages for running optional
tests. Let's avoid this by including all tests in test_all and
turning on/off by flags.

[codecov]

Codecov Report

Merging #35 into master will decrease coverage by 0.94%.
The diff coverage is 82.60%.

@@            Coverage Diff             @@
##           master      #35      +/-   ##
==========================================
- Coverage   91.05%   90.11%   -0.95%     
==========================================
  Files           8        8              
  Lines         246      263      +17     
==========================================
+ Hits          224      237      +13     
- Misses         22       26       +4     

Impacted Files	Coverage Δ
src/Aqua.jl	73.91% <77.77%> (-7.91%)	⬇️
src/utils.jl	91.66% <100.00%> (+1.34%)	⬆️

---

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 c8bf941...318b5bb. Read the comment docs.