Added config file for integration points with govuk-prototype-kit.

To accompany the extensions proposal this config allows govuk-frontend to be an extension in the prototype kit.

Implementation details can be found here alphagov/govuk-prototype-kit#613
Proposal details can be found here alphagov/govuk-design-system-architecture#9

package/govuk-prototype-kit.config.json

@@ -0,0 +1,15 @@
+{
+  "nunjucksPaths": [
+    "/",
+    "/components"
+  ],
+  "scripts": [
+    "/all.js"
+  ],
+  "assets": [
+    "/assets"
+  ],
+  "sass": [
+    "/all.scss"
+  ]
+}

tasks/gulp/__tests__/after-build-package.test.js

@@ -44,16 +44,15 @@ describe('package/', () => {
 
       const additionalFilesNotInSrc = [
         'package.json',
+        'govuk-prototype-kit.config.json',
         '**/macro-options.json'
       ]
 
       return recursive(configPaths.src, filesToIgnore).then(
         files => {
           let filesNotInSrc = files
           // Use glob to generate an array of files that accounts for wildcards in filenames
-          filesNotInSrc = glob.sync('{' + additionalFilesNotInSrc.join(',') + '}')
-            // Remove /package prefix from filenames
-            .map(file => file.replace(/^package\//, ''))
+          filesNotInSrc = glob.sync('{' + additionalFilesNotInSrc.join(',') + '}', { cwd: 'package' })
 
           return files
             // Remove /src prefix from filenames

tasks/gulp/clean.js

@@ -17,6 +17,7 @@ gulp.task('clean', () => {
       `${destination}/**`,
       `!${destination}`,
       `!${destination}/package.json`,
+      `!${destination}/govuk-prototype-kit.config.json`,
       `!${destination}/README.md`
     ])
   } else {