Support scoped packages for cra --scripts-version option (facebook#4677)

Author: Jack Zhao

packages/create-react-app/createReactApp.js

@@ -214,7 +214,9 @@ function createApp(name, verbose, version, useNpm, template) {
   if (!semver.satisfies(process.version, '>=6.0.0')) {
     console.log(
       chalk.yellow(
-        `You are using Node ${process.version} so the project will be bootstrapped with an old unsupported version of tools.\n\n` +
+        `You are using Node ${
+          process.version
+        } so the project will be bootstrapped with an old unsupported version of tools.\n\n` +
           `Please update to Node 6 or higher for a better, fully supported experience.\n`
       )
     );
@@ -228,7 +230,9 @@ function createApp(name, verbose, version, useNpm, template) {
       if (npmInfo.npmVersion) {
         console.log(
           chalk.yellow(
-            `You are using npm ${npmInfo.npmVersion} so the project will be boostrapped with an old unsupported version of tools.\n\n` +
+            `You are using npm ${
+              npmInfo.npmVersion
+            } so the project will be boostrapped with an old unsupported version of tools.\n\n` +
               `Please update to npm 3 or higher for a better, fully supported experience.\n`
           )
         );
@@ -409,7 +413,7 @@ function getInstallPackage(version, originalDirectory) {
   if (validSemver) {
     packageToInstall += `@${validSemver}`;
   } else if (version) {
-    if (version[0] === '@') {
+    if (version[0] === '@' && version.indexOf('/') === -1) {
       packageToInstall += version;
     } else if (version.match(/^file:/)) {
       packageToInstall = `file:${path.resolve(