fix: upgrade slugify from 1.3.1 to 1.6.0

Snyk has created this PR to upgrade slugify from 1.3.1 to 1.6.0.

See this package in npm:
https://www.npmjs.com/package/slugify

See this project in Snyk:
https://app.snyk.io/org/reactioncommerce/project/536303cd-177f-47dd-aa8b-35217cef374d?utm_source=github&utm_medium=upgrade-pr

package.json

@@ -163,7 +163,7 @@
     "semantic-release": "^17.4.3",
     "shallowequal": "^1.0.2",
     "simpl-schema": "1.10.2",
-    "slugify": "1.3.1",
+    "slugify": "1.6.0",
     "store": "^2.0.12",
     "stripe": "^7.10.0",
     "styled-components": "3.4.2",