fix: pubdev/package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/npm:lodash:20180130

Author: snyk-bot

pubdev/package.json

@@ -71,7 +71,7 @@
     "react-tag-autocomplete": "^5.4.1",
     "react-tag-input": "^4.0.0",
     "react-time": "^4.0.0",
-    "react-tinymce": "^0.5.1",
+    "react-tinymce": "^0.6.0",
     "react-transition-group": "^2.2.1",
     "recompose": "^0.26.0",
     "semantic-ui-react": "^0.67.2",