Fix typo in kitchen.yml (facebook#256)

Summary:
kitchen.yml had a typo that was preventing debian containers from
using systemd which was causing a lot of failures.

This is based on top of facebook#255 - and together Debian kitchen tests
now pass.

Signed-off-by: Phil Dibowitz <phil@ipom.com>

Pull Request resolved: facebook#256

Differential Revision: D69316906

fbshipit-source-id: 34695b920ea7a21641a2255e6ad19fc93876ee62

Author: jaymzh

.kitchen.yml

@@ -35,11 +35,11 @@ platforms:
   - name: debian-9
     driver:
       image: dokken/debian-9
-      pid_one_commmand: /bin/systemd
+      pid_one_command: /bin/systemd
   - name: debian-10
     driver:
       image: dokken/debian-10
-      pid_one_commmand: /bin/systemd
+      pid_one_command: /bin/systemd
 
 provisioner:
   name: dokken