Updated build instructions to remove --prod

docs/development.md

@@ -248,7 +248,7 @@ Testing and code style:
 In order to build the front end and serve it as part of django, execute
 
 ```shell-session
-$ ng build --prod
+$ ng build --configuration production
 ```
 
 This will build the front end and put it in a location from which the

src-ui/README.md

@@ -12,7 +12,7 @@ Run `ng generate component component-name` to generate a new component. You can
 
 ## Build
 
-Run `ng build` to build the project. The build artifacts will be stored in the `dist/` directory. Use the `--prod` flag for a production build.
+Run `ng build` to build the project. The build artifacts will be stored in the `dist/` directory. Use the `--configuration production` flag for a production build.
 
 ## Running unit tests
 

src-ui/src/environments/environment.ts

@@ -1,5 +1,5 @@
 // This file can be replaced during build by using the `fileReplacements` array.
-// `ng build --prod` replaces `environment.ts` with `environment.prod.ts`.
+// `ng build --configuration production` replaces `environment.ts` with `environment.prod.ts`.
 // The list of file replacements can be found in `angular.json`.
 
 export const environment = {