Bug 939324 - Purge before building. r=aki
Bug 939324 - Purge before building. r=aki

--HG--
branch : production
extra : transplant_source : %1C%405%FF%256%05m5%F3%EC%A3%E5F%3B%B1%11%AC%3D%CB

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