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 56a900dd.

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"