Added the ability to reload the promise constructor;

[DigitalBrainJS]

It would be nice to be able to choose the Promise constructor to compose the middleware. This does not affect performance in any way but makes the helper more flexible. At least it would be useful in my task.

[codecov[bot]]

Codecov Report

Merging #135 (c288793) into master (20b7f57) will not change coverage. The diff coverage is 100.00%.

:exclamation: Current head c288793 differs from pull request most recent head bf2be85. Consider uploading reports for the commit bf2be85 to get more accurate results

@@            Coverage Diff            @@
##            master      #135   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            1         1           
  Lines           17        20    +3     
  Branches         5         7    +2     
=========================================
+ Hits            17        20    +3     

Impacted Files	Coverage Δ
index.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 20b7f57...bf2be85. Read the comment docs.