Add require snippet

Change-Id: I4b26542922ae6399485e04313e413ae6735e5ef6
Migrate to UltiSnips format

Change-Id: Ifabb03d4afa15da9ae2b128bccd6908b5db3c3a8
Add Mocha js snippets

Change-Id: I330b04a4f0f71da14bea70d77e946cf9698330b2