Change Makefile to use local eslint

Changes the Makefile lint target to use the local copy of
eslint that would be installed in node_modules rather than
a global copy that may not be installed.

Author: sehrope

Makefile

@@ -62,4 +62,4 @@ test-pool:
 
 lint:
 	@echo "***Starting lint***"
-	eslint lib
+	node_modules/.bin/eslint lib