pkgng: add test for autoremove=yes

Install package with known dependencies, then
remove it and ask autoremove to run.

tests/integration/targets/pkgng/tasks/freebsd.yml

@@ -253,6 +253,40 @@
       - "(pkgng_example6.stdout | regex_findall('will be affected', multiline=True) | count) == 2"
       - pkgng_example6_cleanup.changed
 
+##
+## pkgng - example - autoremove=yes
+##
+- name: Install GNU autotools
+  pkgng:
+    name: autotools
+    state: latest
+  register: pkgng_example7_prepare_install
+
+- name: Remove GNU autotools and run pkg autoremove
+  pkgng:
+    name: autotools
+    state: absent
+    autoremove: yes
+  register: pkgng_example7
+
+- name: Check if autoremove uninstalled known autotools dependencies
+  pkgng:
+    name:
+      - autoconf
+      - automake
+      - libtool
+      - m4
+    state: absent
+  check_mode: yes
+  register: pkgng_example7_cleanup
+
+- name: Ensure pkgng autoremove works correctly
+  assert:
+    that:
+      - pkgng_example7_prepare_install.changed
+      - "'autoremoved' is in(pkgng_example7.msg)"
+      - not pkgng_example7_cleanup.changed
+
 ##
 ## pkgng - example - Install single package in jail
 ##