fix: .snyk & package.json to reduce vulnerabilities

The following vulnerabilities are fixed with a Snyk patch:
- https://snyk.io/vuln/npm:lodash:20180130

Author: snyk-bot

.snyk

@@ -35,3 +35,6 @@ patch:
         patched: '2018-06-21T08:42:28.287Z'
     - hubot-slack > @slack/client > request > hawk > cryptiles > boom > hoek:
         patched: '2018-06-21T08:42:28.287Z'
+  'npm:lodash:20180130':
+    - hubot-slack > lodash:
+        patched: '2018-07-05T08:38:07.105Z'

package.json

@@ -22,7 +22,7 @@
     "hubot-slack": "^4.0.0",
     "lodash": "^4.12.0",
     "node-schedule": "^1.2.0",
-    "snyk": "^1.83.0"
+    "snyk": "^1.88.1"
   },
   "engines": {
     "node": "0.10.x"