Add kickstart.user.root?

docs/index.md

@@ -43,3 +43,4 @@
 * [kickstart.user.exec](kickstart/user/exec)
 * [kickstart.user.is_on_group](kickstart/user/is_on_group)
 * [kickstart.user.remove_group](kickstart/user/remove_group)
+* [kickstart.user.root?](kickstart/user/root?)

docs/kickstart/user/root?.md

@@ -0,0 +1,13 @@
+# kickstart.user.root?
+
+Return 0 if the user running is root and 1 if not.
+
+
+### Example
+
+```bash
+$ whoami
+root
+$ kickstart.user.root? && echo yup
+yup
+```