Fix combinated run of unarchive and uri tests under centos 6

The unarchive integration test installs pinned packages via pip,
the uri test installs them from system packages. This explodes.
PR lets unarchive uninstall packages after test ran.

test/integration/targets/unarchive/tasks/test_download.yml

@@ -4,7 +4,9 @@
     path: '{{remote_tmp_dir}}/test-unarchive-tar-gz'
     state: directory
 
-- name: Install packages to make TLS connections work on CentOS 6
+- name: Test TLS download
+  block:
+  - name: Install packages to make TLS connections work on CentOS 6
     pip:
       name:
         - urllib3==1.10.2
@@ -14,21 +16,29 @@
     when:
       - ansible_facts.distribution == 'CentOS'
       - not ansible_facts.python.has_sslcontext
-
+  - name: unarchive a tar from an URL
-- name: unarchive a tar from an URL
     unarchive:
       src: "https://releases.ansible.com/ansible/ansible-latest.tar.gz"
       dest: "{{ remote_tmp_dir }}/test-unarchive-tar-gz"
       mode: "0700"
       remote_src: yes
     register: unarchive13
-
+  - name: Test that unarchive succeeded
-- name: Test that unarchive succeeded
     assert:
       that:
         - "unarchive13.changed == true"
-
+  always:
-- name: remove our tar.gz unarchive destination
+    - name: Uninstall CentOS 6 TLS connections packages
+      pip:
+        name:
+          - urllib3
+          - ndg_httpsclient
+          - pyOpenSSL
+        state: absent
+      when:
+        - ansible_facts.distribution == 'CentOS'
+        - not ansible_facts.python.has_sslcontext
+    - name: remove our tar.gz unarchive destination
       file:
         path: '{{ remote_tmp_dir }}/test-unarchive-tar-gz'
         state: absent