Update Ansible tasks to run as skywalking user (#21)

diff --git a/README.md b/README.md
index d6d9ca7..5c91f17 100644
--- a/README.md
+++ b/README.md
@@ -117,7 +117,7 @@
 Save the SSH key file path generated by Terraform to a variable for future use:
 
 ```
-cd ansible
+cd ../ansible/
 SSH_KEY_FILE=$(terraform -chdir=../aws output -raw ssh-user-key-file)
 echo $SSH_KEY_FILE
 ```
diff --git a/ansible/playbooks/install-skywalking.yml b/ansible/playbooks/install-skywalking.yml
index b7e3902..2fde5ea 100644
--- a/ansible/playbooks/install-skywalking.yml
+++ b/ansible/playbooks/install-skywalking.yml
@@ -14,15 +14,22 @@
 # limitations under the License.
 
 ---
-- hosts: all
+- name: Create skywalking group
+  hosts: all
   gather_facts: false
   tasks:
-  - name: Create user skywalking
-    become: true
-    user:
-      name: skywalking
-      group: skywalking
-      state: present
+    - group:
+        name: skywalking
+        state: present
+
+- name: Create skywalking user
+  hosts: all
+  gather_facts: false
+  tasks:
+    - user:
+        name: skywalking
+        group: skywalking
+        state: present
 
 - name: Install Java
   hosts: all
diff --git a/ansible/roles/skywalking/tasks/main.yml b/ansible/roles/skywalking/tasks/main.yml
index 0d55e23..c25b823 100644
--- a/ansible/roles/skywalking/tasks/main.yml
+++ b/ansible/roles/skywalking/tasks/main.yml
@@ -49,11 +49,11 @@
     oap_bundled: "{{ groups['skywalking_oap'][1:] if groups['skywalking_oap'] | length > 1 else [] }}"
 
 - name: Run the OAPSericeInit script
-  shell: /usr/local/skywalking/bin/oapServiceInit.sh
+  shell: "sudo -u skywalking /usr/local/skywalking/bin/oapServiceInit.sh"
   when: inventory_hostname in oap_standalone
 
 - name: Run the OAPSericeNoInit script
-  shell: /usr/local/skywalking/bin/oapServiceNoInit.sh
+  shell: "sudo -u skywalking /usr/local/skywalking/bin/oapServiceNoInit.sh"
   when: inventory_hostname in oap_bundled
 
 - name: Generate systemd unit file for oap service