Make sure when argument corresponds with then arguments

[braker1nine]

Addresses #114

Basically if you use arguments to pass promises to Parse.Promise.when, then use arguments to pass the results to any resulting then call. If you use an array, then pass an array to the then call

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[codecov-io]

Current coverage is 78.64%

Merging #115 into master will decrease coverage by -0.02% as of 5725669

@@            master    #115   diff @@
======================================
  Files           37      37       
  Stmts         2822    2824     +2
  Branches       677     678     +1
  Methods          0       0       
======================================
+ Hit           2220    2221     +1
+ Partial        189     188     -1
- Missed         413     415     +2

Review entire Coverage Diff as of 5725669

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[andrewimm]

Looks good