Merge pull request #15 from ideal-postcodes/dependabot/npm_and_yarn/chai-approx-4.2.0

Update chai requirement from ~1.8.1 to ~4.2.0

Author: cblanc

package.json

@@ -11,7 +11,7 @@
   "devDependencies": {
     "mocha": "~1.17.0",
     "csv": "~0.3.6",
-    "chai": "~1.8.1"
+    "chai": "~4.2.0"
   },
   "scripts": {
     "test": "mocha tests/"