install python packages for testing

playbooks/roles/jenkins_worker/tasks/android_testing_tools.yml

+---
+
+# Install Python packages used for testing the edX Android app on Jenkins
+# Note: normally, we use a virtual environment for pip installs on a Jenkins 
+# worker, but since this is the only instance of python being used on the machine
+# we install them as system packages. If we start requiring more python, or
+# add other jobs to this worker, please reconsider this.
+- name: Install Android testing requirements using pip
+  pip:
+    name: "{{ item }}"
+    state: present
+    extra_args: "--user --exists-action=w"
+    executable: pip
+  with_items:
+    - pillow
+    - codecov

playbooks/roles/jenkins_worker/tasks/main.yml

@@ -14,6 +14,10 @@
 - include: python_platform_worker.yml
   when: platform_worker is defined
 
+# Only Android workers
+- include: android_testing_tools.yml
+  when: android_worker is defined
+
 # Run appropriate tests
 - include: test.yml
 - include: test_platform_worker.yml