* Preserve null in babel-types' clone and deepClone. * Also respect undefined when cloning. * Updating last test to reflect original test case "[,0]"
* Add tests for path type inferers * Add test for babel-types.valueToNode * Add tests for babel-types.toKeyAlias * Add tests for babel-types.toStatement * Add tests for babel-types.toExpression * Lint fixes in babel-traverse/test/inference