➖ remove unused dependencies. Closes #272

- `request`
- `request-promise`

`request` first appeared as part of initial commit but it seems to be
left-over from non commited implementation:
https://git.io/JvgNV
`request-promise` was added in different PR but it seems without related
code:
https://git.io/JvgN6

/cc @naknode

Thanks!

package.json

@@ -48,8 +48,6 @@
         "passport-facebook": "^3.0.0",
         "passport-local": "^1.0.0",
         "pug": "^2.0.4",
-        "request": "^2.88.0",
-        "request-promise": "^4.2.4",
         "winston": "^3.2.1"
     },
     "devDependencies": {