Systemd units, limits, and bin path fixes

* Add restart for weave service unit
* Reuse docker_bin_dir everythere
* Limit systemd managed docker containers by CPU/RAM. Do not configure native
  systemd limits due to the lack of consensus in the kernel community
  requires out-of-tree kernel patches.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

roles/reset/tasks/main.yml

@@ -21,7 +21,7 @@
   when: ansible_service_mgr == "systemd" and services_removed.changed
 
 - name: reset | remove all containers
-  shell: docker ps -aq | xargs -r docker rm -fv
+  shell: "{{ docker_bin_dir }}/docker ps -aq | xargs -r docker rm -fv"
 
 - name: reset | gather mounted kubelet dirs
   shell: mount | grep /var/lib/kubelet | awk '{print $3}' | tac