chore(git): add yarn-cache to gitignore

Peter Svetlichny · Peter Svetlichny · commit 4998f15bb4a9 · 2017-09-16T14:11:28.000-07:00
diff --git a/.gitignore b/.gitignore
@@ -8,4 +8,5 @@ docs
 .idea/
 _builds/
 _projects/
-_steps/
+_steps/
+.yarn-cache
