chore: @types/should no longer needed

Author: citizensas

package.json

@@ -24,7 +24,6 @@
   "devDependencies": {
     "@types/form-data": "2.2.0",
     "@types/mocha": "2.2.43",
-    "@types/should": "11.2.0",
     "codecov": "2.3.0",
     "dateformat": "3.0.0",
     "execa": "0.8.0",