fix(create-cedar-app): Include @cedarjs/testing as devDep (#162)

The `@cedarjs/testing` package is used by the project when testing, so
should be included in the list of dev dependencies

Author: Tobbe

__fixtures__/test-project/package.json

@@ -9,6 +9,7 @@
   "devDependencies": {
     "@cedarjs/core": "0.0.5",
     "@cedarjs/project-config": "0.0.5",
+    "@cedarjs/testing": "0.0.5",
     "prettier-plugin-tailwindcss": "^0.5.12"
   },
   "eslintConfig": {

packages/create-cedar-app/templates/js/package.json

@@ -8,7 +8,8 @@
   },
   "devDependencies": {
     "@cedarjs/core": "0.0.5",
-    "@cedarjs/project-config": "0.0.5"
+    "@cedarjs/project-config": "0.0.5",
+    "@cedarjs/testing": "0.0.5"
   },
   "eslintConfig": {
     "extends": "@cedarjs/eslint-config",

packages/create-cedar-app/templates/ts/package.json

@@ -8,7 +8,8 @@
   },
   "devDependencies": {
     "@cedarjs/core": "0.0.5",
-    "@cedarjs/project-config": "0.0.5"
+    "@cedarjs/project-config": "0.0.5",
+    "@cedarjs/testing": "0.0.5"
   },
   "eslintConfig": {
     "extends": "@cedarjs/eslint-config",