Update build to use gradle apis for file paths.

[igorbernstein2]

This allows individual tests to be run using intellij's gradle runner. Otherwise they fail to find the version file

[codecov-io]

Codecov Report

Merging #434 into master will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #434   +/-   ##
=========================================
  Coverage     70.53%   70.53%           
  Complexity      634      634           
=========================================
  Files           136      136           
  Lines          2912     2912           
  Branches        220      220           
=========================================
  Hits           2054     2054           
  Misses          776      776           
  Partials         82       82

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[garrettjonesgoogle]

LGTM.

I see there are other places using "new File" - should we update the rest of them too? Your change implies that file(...) is more idiomatic in Gradle.

[igorbernstein2]

I'm not a gradle expert, but I think so. I only fixed the places that prevented me from iterating quickly on the streaming callable