added --spa to cli options

lib/cli-options.js

@@ -29,6 +29,10 @@ module.exports = {
       description: 'A list of URL rewrite rules', group: 'server'
     },
     {
+      name: 'spa', alias: 's', type: String,
+      description: 'Single Page App page', group: 'server'
+    },
+    {
       name: 'help', alias: 'h', type: Boolean,
       description: 'Print these usage instructions', group: 'misc'
     },

lib/local-web-server.js

@@ -130,7 +130,7 @@ function localWebServer (options) {
   if (options.spa) {
     const send = require('koa-send')
     app.use(_.all('*', function * () {
-      yield send(this, options.spa, { root: options.static.root || process.cwd() })
+      yield send(this, options.spa, { root: path.resolve(options.static.root) || process.cwd() })
     }))
   }
   return app