feat: Refactor code with modern settings

BREAKING CHANGE: We now require Node.js v10.12.0 or newer.
* We now only work with Redis v3.0.0 or newer.
* `Redis` can't be called as a function anymore as it's now a class.
Please change `Redis()` to `new Redis()`. Note that `Redis()` was already deprecated
in the previous version.

Author: luin

.eslintrc.json

@@ -0,0 +1,40 @@
+{
+  "extends": [
+    "eslint:recommended",
+    "plugin:@typescript-eslint/recommended",
+    "plugin:@typescript-eslint/eslint-recommended",
+    "prettier"
+  ],
+  "parser": "@typescript-eslint/parser",
+  "plugins": ["@typescript-eslint"],
+  "env": { "node": true },
+  "rules": {
+    "prefer-rest-params": 0,
+    "no-var": 0,
+    "no-prototype-builtins": 0,
+    "prefer-spread": 0,
+    "@typescript-eslint/no-var-requires": 0,
+    "@typescript-eslint/no-explicit-any": 0,
+    "@typescript-eslint/no-this-alias": 0,
+    "@typescript-eslint/ban-ts-ignore": 0,
+    "@typescript-eslint/ban-ts-comment": 0,
+    "@typescript-eslint/ban-types": 0,
+    "@typescript-eslint/no-empty-interface": 0,
+    "@typescript-eslint/no-empty-function": 0,
+    "@typescript-eslint/no-unused-vars": [
+      "warn",
+      {
+        "args": "none"
+      }
+    ]
+  },
+  "overrides": [
+    {
+      "files": ["test/**/*"],
+      "env": {
+        "mocha": true
+      },
+      "rules": { "prefer-const": 0 }
+    }
+  ]
+}