Revert "Use git to get the branch name and commit number, rather than incoming…

Revert "Use git to get the branch name and commit number, rather than incoming environment variables"

This reverts commit d6a57558.

rakefile

@@ -10,8 +10,8 @@ DEPLOY_DIR = "/opt/packages"
 PACKAGE_NAME = "mitx"
 LINK_PATH = "/opt/wwc/mitx"
 VERSION = "0.1"
-COMMIT = `git rev-parse HEAD`.chomp()[0, 10]
-BRANCH = `git symbolic-ref -q HEAD`.chomp().gsub('refs/heads/', '').gsub('origin/', '').gsub('/', '_').downcase()
+COMMIT = (ENV["GIT_COMMIT"] || `git rev-parse HEAD`).chomp()[0, 10]
+BRANCH = (ENV["GIT_BRANCH"] || `git symbolic-ref -q HEAD`).chomp().gsub('refs/heads/', '').gsub('origin/', '').gsub('/', '_').downcase()
 BUILD_NUMBER = (ENV["BUILD_NUMBER"] || "dev").chomp()
 
 if BRANCH == "master"