Upgrade to TypeScript 2.4

[kitsonk]

Type: feature

The following has been addressed in the PR:

• There is a related issue
• All code matches the style guide
• Unit or Functional tests are included in the PR

Description:

This PR updates the loader to use TypeScript 2.4.

Refs dojo/meta#189

[codecov]

Codecov Report

Merging #140 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #140   +/-   ##
=======================================
  Coverage   85.87%   85.87%           
=======================================
  Files           1        1           
  Lines         545      545           
  Branches      135      135           
=======================================
  Hits          468      468           
  Misses         32       32           
  Partials       45       45

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[agubler]

Closing as I accidentally raised another one.