fix(@angular/cli): remove -bo alias for --build-optimizer

/cc @StephenFluin

Author: filipesilva

packages/@angular/cli/commands/build.ts

@@ -163,7 +163,6 @@ export const baseBuildCommandOptions: any = [
     name: 'build-optimizer',
     type: Boolean,
     default: false,
-    aliases: ['bo'],
     description: '(Experimental) Enables @angular-devkit/build-optimizer '
     + 'optimizations when using `--aot`.'
   },

tests/e2e/tests/build/build-optimizer.ts

@@ -4,7 +4,7 @@ import { expectToFail } from '../../utils/utils';
 
 
 export default function () {
-  return ng('build', '--aot', '--bo')
+  return ng('build', '--aot', '--build-optimizer')
     .then(() => expectToFail(() => expectFileToExist('dist/vendor.js')))
     .then(() => expectToFail(() => expectFileToMatch('dist/main.js', /\.decorators =/)));
 }