Add AIO_DEV env flag to detect running local (#151)

* add AIO_DEV env flag to detect running local

Author: purplecabbage

src/lib/run-dev.js

@@ -81,6 +81,10 @@ async function runDev (runOptions, config, _inprocHookRunner) {
   process.env.__OW_API_KEY = process.env.AIO_RUNTIME_AUTH
   process.env.__OW_NAMESPACE = process.env.AIO_RUNTIME_NAMESPACE
   process.env.__OW_API_HOST = process.env.AIO_RUNTIME_APIHOST
+  // set up environment variables for aio
+  // this can be read as truthy, it will not exist in Runtime
+  // ex. console.log('AIO_DEV ', process.env.AIO_DEV ? 'dev' : 'prod')
+  process.env.AIO_DEV = 'true'
 
   const serverPortToUse = parseInt(process.env.PORT) || SERVER_DEFAULT_PORT
   const serverPort = await getPort({ port: serverPortToUse })