Improve tests: don't install daemon when running inside a container (#56)

* If running inside a container, only install docker CLI, not docker daemon.

ci_complete

* Fix OpenSUSE.

tests/integration/targets/setup_docker/vars/Debian.yml

@@ -1,3 +1,4 @@
+---
 docker_prereq_packages:
   - apt-transport-https
   - ca-certificates

tests/integration/targets/setup_docker/vars/Fedora.yml

@@ -1,4 +1 @@
-docker_prereq_packages: []
-
-docker_packages:
-  - docker-ce
+---

tests/integration/targets/setup_docker/vars/RedHat-7.yml

@@ -1,3 +1,4 @@
+---
 docker_prereq_packages:
   - yum-utils
   - device-mapper-persistent-data

tests/integration/targets/setup_docker/vars/RedHat-8.yml

@@ -1,3 +1,4 @@
+---
 docker_prereq_packages:
   - yum-utils
   - device-mapper-persistent-data
@@ -7,3 +8,5 @@ docker_prereq_packages:
 docker_packages:
   - docker-ce-19.03.13
   - docker-ce-cli-19.03.13
+docker_cli_packages:
+  - docker-ce-cli-19.03.13

tests/integration/targets/setup_docker/vars/Suse.yml

@@ -1,2 +1,8 @@
+---
 docker_packages:
   - docker>=17
+
+# OpenSUSE 15 does not seem to have docker-client (https://software.opensuse.org/package/docker-client)
+# or any other Docker CLI-only package
+docker_cli_packages:
+  - docker>=17

tests/integration/targets/setup_docker/vars/Ubuntu-14.yml

@@ -1,3 +1,4 @@
+---
 docker_pip_extra_packages:
   # Installing requests >=2.12.0 on Ubuntu 14.04 breaks certificate validation. We restrict to an older version
   # to ensure out get_url tests work out fine. This is only an issue if pyOpenSSL is also installed.

tests/integration/targets/setup_docker/vars/default.yml

@@ -0,0 +1 @@
+---