bintray: warn on upload error on uploads
bintray: warn on upload error on uploads

Previously this would only warn on errors for certain Bintray API
requests like publishing. This should now also warn on error for curl
POST uploads (if the appropriate flag has been passed).

JCount/brew,reitermarkus/brew,EricFromCanada/brew,Homebrew/brew,konqui/brew,nandub/brew,konqui/brew,vitorgalvao/brew,EricFromCanada/brew,MikeMcQuaid/brew,konqui/brew,nandub/brew,EricFromCanada/brew,sjackman/homebrew,reitermarkus/brew,claui/brew,nandub/brew,JCount/brew,claui/brew,MikeMcQuaid/brew,sjackman/homebrew,vitorgalvao/brew,MikeMcQuaid/brew,Homebrew/brew,reitermarkus/brew,JCount/brew,claui/brew,nandub/brew,Homebrew/brew,Homebrew/brew,EricFromCanada/brew,MikeMcQuaid/brew,vitorgalvao/brew,sjackman/homebrew,JCount/brew,claui/brew,vitorgalvao/brew,reitermarkus/brew,sjackman/homebrew,konqui/brew