actually add the command

Author: Shywim

package.json

@@ -54,6 +54,7 @@
     "build": "babel src -d lib --ignore '*.test.js'",
     "watch": "babel --watch src -d lib --ignore '*.test.js'",
     "test-gen": "rm -rf ./tmp && yarn build && ./lib/index.js https://demo.api-platform.com ./tmp/react -g react && ./lib/index.js https://demo.api-platform.com ./tmp/react-native -g react-native && ./lib/index.js https://demo.api-platform.com ./tmp/vue -g vue",
+    "test-gen-custom": "rm -rf ./tmp && yarn build && babel src/generators/ReactGenerator.js src/generators/BaseGenerator.js -d ./tmp/gens && cp -r ./templates/react ./templates/react-common ./templates/entrypoint.js ./tmp/gens && ./lib/index.js https://demo.api-platform.com ./tmp/react-custom --custom-generator \"$(pwd)/tmp/gens/ReactGenerator.js\" -t ./tmp/gens",
     "test-gen-swagger": "rm -rf ./tmp && yarn build && ./lib/index.js  https://demo.api-platform.com/docs.json ./tmp/react -f swagger && ./lib/index.js https://demo.api-platform.com/docs.json ./tmp/react-native -g react-native -f swagger && ./lib/index.js https://demo.api-platform.com/docs.json ./tmp/vue -g vue -f swagger",
     "test-gen-env": "rm -rf ./tmp && yarn build && API_PLATFORM_CLIENT_GENERATOR_ENTRYPOINT=https://demo.api-platform.com API_PLATFORM_CLIENT_GENERATOR_OUTPUT=./tmp ./lib/index.js"
   },