fix(cli): use rimraf to replace rm -rf

Author: raymondfeng

packages/cli/generators/project/templates/package.plain.json.ejs

@@ -14,7 +14,7 @@
     "build": "tsc --outDir dist --target es2017",
     "build:all-dist": "npm run build",
     "build:watch": "tsc --outDir dist --target es2017 --watch",
-    "clean": "rm -rf dist",
+    "clean": "rimraf dist",
 <% if (project.prettier && project.tslint) { -%>
     "lint": "npm run prettier:check && npm run tslint",
     "lint:fix": "npm run tslint:fix && npm run prettier:fix",
@@ -79,6 +79,7 @@
 <% } -%>
   },
   "devDependencies": {
+    "rimraf": "<%= project.dependencies['rimraf'] -%>",
     "@loopback/testlab": "<%= project.dependencies['@loopback/testlab'] -%>",
 <% if (project.mocha) { -%>
     "@types/mocha": "<%= project.dependencies['@types/mocha'] -%>",

packages/cli/test/integration/lib/project-generator.js

@@ -330,13 +330,15 @@ module.exports = function(projGenerator, props, projectType) {
           'package.json',
           `"@loopback/context": "${deps['@loopback/context']}"`,
         );
+        assert.fileContent('package.json', `"rimraf": "${deps['rimraf']}"`);
         assert.noFileContent([
           ['package.json', '@loopback/build'],
           ['package.json', '@loopback/dist-util'],
           ['tslint.json', '@loopback/build'],
           ['tsconfig.json', '@loopback/build'],
         ]);
         assert.fileContent([
+          ['package.json', '"clean": "rimraf dist"'],
           ['package.json', '"typescript"'],
           ['package.json', '"tslint"'],
           ['package.json', '"prettier"'],