Test on macs which on ci normally don't have avx2

[chriselrod]

No description provided.

[codecov-io]

Codecov Report

Merging #19 (e4afa71) into master (3e6b3e8) will decrease coverage by 0.86%.
The diff coverage is 35.08%.

@@            Coverage Diff             @@
##           master      #19      +/-   ##
==========================================
- Coverage   87.48%   86.61%   -0.87%     
==========================================
  Files          13       13              
  Lines        1478     1509      +31     
==========================================
+ Hits         1293     1307      +14     
- Misses        185      202      +17     

Impacted Files	Coverage Δ
src/utils.jl	61.90% <25.00%> (ø)
src/double.jl	50.24% <33.33%> (-0.05%)	⬇️
src/trig.jl	100.00% <100.00%> (ø)
src/exp.jl	97.19% <0.00%> (-1.87%)	⬇️

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