Add build script and adapt manifest for the build script to work

RoboFile.dist.ini

@@ -0,0 +1,16 @@
+; If set to true, the repo will not be cloned from GitHub and the local copy will be reused.
+; This setting will be obsolete once we have local Git cache enabled
+skipClone = false
+
+; If you want to setup your test website in a different folder, you can do that here.
+; You can also set an absolute path, i.e. /path/to/my/cms/folder
+cmsPath = tests/joomla
+
+; If you want to clone a different branch, you can set it here
+branch = 4.0-dev
+
+; (Linux / Mac only) If you want to set a different owner for the CMS root folder, you can set it here.
+localUser = www-data
+
+; Set this to true, if your curl binaries are not able to create an https connection
+insecure = false