Bug 898554 - Extract logic for generating build commands, r=aki
Bug 898554 - Extract logic for generating build commands, r=aki

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extra : rebase_source : b777c4bc2a9d6e3acf51dad703057961eb138434

simar7/build-mozharness,armenzg/build-mozharness,escapewindow/mozharness,kartikgupta0909/gittest,walac/build-mozharness,simar7/build-mozharness,mozilla/build-mozharness,mrrrgn/build-mozharness,mrrrgn/build-mozharness,lissyx/build-mozharness,mozilla/build-mozharness,walac/build-mozharness,escapewindow/mozharness,kartikgupta0909/mozilla-mozharness,kartikgupta0909/mozilla-mozharness,armenzg/build-mozharness,kartikgupta0909/gittest,kartikgupta0909/build-mozharness,kartikgupta0909/build-mozharness,lissyx/build-mozharness