Need to install java on all machines (OAP and UI) (#11)

diff --git a/ansible/playbooks/install-skywalking.yml b/ansible/playbooks/install-skywalking.yml
index 536e23e..1cbff86 100644
--- a/ansible/playbooks/install-skywalking.yml
+++ b/ansible/playbooks/install-skywalking.yml
@@ -15,7 +15,7 @@
 
 ---
 - name: Install Java
-  hosts: skywalking-oap
+  hosts: all
   gather_facts: true
   roles:
     - install-java