feat: make mongodb a peer dependency

Author: vladholubiev

package.json

@@ -26,15 +26,18 @@
   "dependencies": {
     "cwd": "0.10.0",
     "debug": "4.1.1",
-    "mongodb": "3.2.7",
     "mongodb-memory-server": "5.1.5"
   },
+  "peerDependencies": {
+    "mongodb": "3.x.x"
+  },
   "devDependencies": {
     "@shelf/eslint-config": "0.3.10",
-    "eslint": "5.16.0",
-    "husky": "2.7.0",
+    "eslint": "6.0.1",
+    "husky": "3.0.0",
     "jest": "24.8.0",
-    "lint-staged": "8.2.1",
+    "lint-staged": "9.0.2",
+    "mongodb": "3.2.7",
     "prettier": "1.18.2"
   },
   "jest": {

readme.md

@@ -10,6 +10,8 @@
 $ yarn add @shelf/jest-mongodb --dev
 ```
 
+Make sure `mongodb` is installed in the project as well, as it's required as a peer dependency.
+
 ### 1. Create `jest.config.js`
 
 ```js