Revert "Check out OCG/node_modules as a git submodule."

This reverts commit 27ae9fcbf44cef26d50e971bf5510c16814a9530.

Let's have Jenkins check out node_modules instead.

Change-Id: Iadd7588e31a383759bb8114aada82087a02bd87e
Merge "Revert "Check out OCG/node_modules as a git submodule.""