Replace ember-cli-eslint with eslint

- Remove ember-cli-eslint dependency and replace it with direct
dependency on eslint and required plugins.

NOTE: disabling no-new-mixins for since prefetch currently relies on
a mixin.

.eslintrc.js

@@ -16,6 +16,7 @@ module.exports = {
     embertest: true,
   },
   rules: {
+    'ember/no-new-mixins': 'off',
   },
   overrides: [
     // node files

package.json

@@ -18,7 +18,6 @@
     "broccoli-asset-rev": "^2.7.0",
     "ember-cli": "~3.8.0",
     "ember-cli-dependency-checker": "^3.0.0",
-    "ember-cli-eslint": "^4.2.3",
     "ember-cli-htmlbars": "^3.0.0",
     "ember-cli-htmlbars-inline-precompile": "^1.0.3",
     "ember-cli-inject-live-reload": "^1.8.2",
@@ -36,9 +35,13 @@
     "ember-source": "~3.7.0",
     "ember-source-channel-url": "^1.1.0",
     "ember-try": "^1.0.0",
-    "eslint-plugin-ember": "^5.2.0",
-    "eslint-plugin-node": "^7.0.1",
+    "eslint": "^6.4.0",
+    "eslint-config-prettier": "^6.3.0",
+    "eslint-plugin-ember": "^7.1.0",
+    "eslint-plugin-node": "^10.0.0",
+    "eslint-plugin-prettier": "^3.1.1",
     "loader.js": "^4.7.0",
+    "prettier": "^1.18.2",
     "qunit-dom": "^0.8.0"
   },
   "keywords": [