use source of faker instead of compiled one

[FezVrasta]

fixes #336

I haven't noticed any problem with my edits, the data is correctly randomized.

Tests fail with:

1) codeToCustomMetadata should catch errors correctly:

      AssertionError: expected { Object (err) } to deeply equal { Object (err) }
      + expected - actual

       {
      -  "err": "SyntaxError: Unexpected token u in JSON at position 26"
      +  "err": "SyntaxError: Unexpected token u"
       }

      at Assertion.assertEqual (plugins/react/node_modules/chai/lib/chai/core/assertions.js:485:19)
      at Assertion.ctx.(anonymous function) [as equal] (plugins/react/node_modules/chai/lib/chai/utils/addMethod.js:41:25)
      at Context.<anonymous> (codeToCustomMetadata.js:34:48)

But it fails even on master, so I don't think it's related to this PR

[mxstbr]

LGTM, @nikgraf?

[nikgraf]

nice, looks good