fix: optionalDependencies -> devDependencies

package.json

@@ -21,16 +21,17 @@
     "@commitlint/cli": "7.2.1",
     "@commitlint/config-conventional": "7.1.2",
     "@commitlint/travis-cli": "7.2.1",
-    "@types/ember": "3.0.25",
+    "@mike-north/js-lib-renovate-config": "1.0.0",
+    "@mike-north/js-lib-semantic-release-config": "1.0.0",
+    "@types/ember__test-helpers": "0.7.6",
     "@types/ember-qunit": "3.4.3",
     "@types/ember-test-helpers": "1.0.4",
     "@types/ember-testing-helpers": "0.0.3",
-    "@types/ember__test-helpers": "0.7.6",
+    "@types/ember": "3.0.25",
     "@types/qunit": "2.5.3",
     "@types/rsvp": "4.0.2",
     "babel-eslint": "10.0.1",
     "broccoli-asset-rev": "3.0.0",
-    "ember-cli": "3.5.1",
     "ember-cli-app-version": "3.2.0",
     "ember-cli-dependency-checker": "3.0.0",
     "ember-cli-htmlbars-inline-precompile": "2.0.0",
@@ -39,30 +40,27 @@
     "ember-cli-tslint": "0.1.4",
     "ember-cli-typescript": "1.5.0",
     "ember-cli-uglify": "2.1.0",
+    "ember-cli": "3.5.1",
     "ember-disable-prototype-extensions": "1.1.3",
     "ember-disable-proxy-controllers": "1.0.2",
     "ember-export-application-global": "2.0.0",
     "ember-load-initializers": "2.0.0",
     "ember-maybe-import-regenerator": "0.1.6",
     "ember-qunit-decorators": "1.4.2",
     "ember-resolver": "5.0.1",
-    "ember-source": "3.5.1",
     "ember-source-channel-url": "1.1.0",
+    "ember-source": "3.5.1",
     "ember-try": "1.1.0",
     "eslint-plugin-ember": "6.0.1",
     "eslint-plugin-node": "8.0.0",
     "eslint-plugin-typescript": "0.14.0",
     "loader.js": "4.7.0",
     "qunit-dom": "0.8.1",
+    "semantic-release": "^15.9.12",
+    "travis-deploy-once": "^5.0.9",
     "typescript": "3.1.6",
     "typescript-eslint-parser": "21.0.1"
   },
-  "optionalDependencies": {
-    "@mike-north/js-lib-renovate-config": "1.0.0",
-    "@mike-north/js-lib-semantic-release-config": "1.0.0",
-    "semantic-release": "^15.9.12",
-    "travis-deploy-once": "^5.0.9"
-  },
   "keywords": [
     "ember-addon",
     "resize"