Add required inputs

Author: ehmicky

manifest.yml

@@ -1,6 +1,7 @@
 name: netlify-plugin-axe
 inputs:
   - name: checkPaths
+    required: true
   - name: resultMode
   - name: debugMode
   - name: testMode

plugin/index.js

@@ -17,11 +17,6 @@ function netlifyPlugin(conf) {
       constants: { PUBLISH_DIR },
       utils: { build }
     }) {
-      if (!checkPaths) {
-        build.failBuild(
-          `checkPaths is undefined - please specify some checkPaths`
-        );
-      }
       const htmlFilePaths = await pluginCore.generateFilePaths({
         fileAndDirPaths: checkPaths,
         PUBLISH_DIR