Bump dev dependencies

Author: cjbj

package.json

@@ -29,9 +29,9 @@
     "url": "git://github.com/oracle/node-oracledb.git"
   },
   "devDependencies": {
-    "mocha": "6.0.2",
+    "mocha": "6.1.4",
     "should": "13.2.3",
-    "async": "2.6.2"
+    "async": "3.1.0"
   },
   "scripts": {
     "test": "mocha --opts test/opts/mocha.opts",