upgrade ansible back to 2.9.4, and fix issue with virtualenv on Mac

tests/ansible/regression/issue_152__virtualenv_python_fails.yml

@@ -1,5 +1,6 @@
 - name: regression/issue_152__virtualenv_python_fails.yml
   any_errors_fatal: true
+  gather_facts: true
   hosts: test-targets
   tasks:
     - custom_python_detect_environment:
@@ -14,6 +15,10 @@
         no_proxy: "{{ lookup('env', 'no_proxy')|default('') }}"
         PATH: "{{ lookup('env', 'PATH') }}"
 
+    # virtualenv on Mac points to /usr/local/Cellar/python/3.7.2_1/bin/python3.7 as the sys.executable
+    # which matches up with the .Python set up in /tmp/issue_152_virtualenv:
+    # .Python -> /usr/local/Cellar/python/3.7.2_1/Frameworks/Python.framework/Versions/3.7/Python
+    # on Mac, lout's sys.executable is the normal /usr/bin/python
     - custom_python_detect_environment:
       vars:
         ansible_python_interpreter: /tmp/issue_152_virtualenv/bin/python
@@ -23,7 +28,12 @@
     - assert:
         that:
           - out.sys_executable == "/tmp/issue_152_virtualenv/bin/python"
-      when: lout.python_version > '2.6'
+      when: lout.python_version > '2.6' and ansible_os_family != 'Darwin'
+
+    - assert:
+        that:
+          - "'/usr/local/Cellar/python' in out.sys_executable"
+      when: lout.python_version > '2.6' and ansible_os_family == 'Darwin'
 
     - file:
         path: /tmp/issue_152_virtualenv

tests/ansible/requirements.txt

@@ -1,4 +1,4 @@
-ansible==2.8.3; python_version >= '2.7'
+ansible==2.9.4; python_version >= '2.7'
 ansible<2.7; python_version < '2.7'
 paramiko==2.3.2  # Last 2.6-compat version.
 hdrhistogram==0.6.1