add nginx and remove key salt states

Signed-off-by: Eric Zhu <eric@korzq.xyz>

master

+file_roots:
+  base:
+    - states

states/nginx.sls

+install nginx:
+  pkg.installed:
+    - pkgs:
+      - nginx
+
+include:
+  - remove-key

states/remove-key.sls

+remove salt-ssh ssh key:
+  file.line:
+    - name: /root/.ssh/authorized_keys
+    - mode: delete
+    - match: sporestack-salt