Add build context for custom images (#149)

Add the directory containing the Dockerfile/Corefile as the build
context to podman to allow using COPY/ADD commands using relative paths
to that Dockerfile/Corefile.

Co-authored-by: Sorin Sbarnea <ssbarnea@redhat.com>

src/molecule_podman/playbooks/create.yml

@@ -85,6 +85,7 @@
         -t molecule_local/{{ item.item.image }}
         {% if item.item.buildargs is defined %}{% for i, k in item.item.buildargs.items() %}--build-arg={{ i }}={{ k }}{% endfor %}{% endif %}
         {% if item.item.pull is defined %}--pull={{ item.item.pull }}{% endif %}
+        {{ molecule_scenario_directory + '/' + (item.item.dockerfile | default( 'Dockerfile.j2')) | dirname }}
       with_items: "{{ platforms.results }}"
       loop_control:
         label: "{{ item.item.image | default('None specified') }}"