remove python-memcached as a base dependency for playbook execution

docs/custom_virtualenvs.md

@@ -26,10 +26,10 @@ the semantics for creating virtualenvs in Python 3 has changed slightly:
     $ sudo python3 -m venv /var/lib/awx/venv/my-custom-venv
 
 Your newly created virtualenv needs a few base dependencies to properly run
-playbooks (awx uses memcached as a holding space for playbook artifacts and
+playbooks:
 fact gathering):
 
-    $ sudo /var/lib/awx/venv/my-custom-venv/bin/pip install python-memcached psutil
+    $ sudo /var/lib/awx/venv/my-custom-venv/bin/pip install psutil
 
 From here, you can install _additional_ Python dependencies that you care
 about, such as a per-virtualenv version of ansible itself:
@@ -61,7 +61,7 @@ index aa8b304..eb05f91 100644
  
 +requirements_custom:
 +	virtualenv $(VENV_BASE)/my-custom-env
-+	$(VENV_BASE)/my-custom-env/bin/pip install python-memcached psutil
++	$(VENV_BASE)/my-custom-env/bin/pip install psutil
 +
 diff --git a/installer/image_build/templates/Dockerfile.j2 b/installer/image_build/templates/Dockerfile.j2
 index d69e2c9..a08bae5 100644
@@ -97,7 +97,7 @@ Now create an initContainer stanza.  You can subsititute your own custom images
               pip install virtualenv &&
               virtualenv /var/lib/awx/venv/my-custom-venv &&
               source /var/lib/awx/venv/my-custom-venv/bin/activate &&
-              /var/lib/awx/venv/my-custom-venv/bin/pip install python-memcached psutil &&
+              /var/lib/awx/venv/my-custom-venv/bin/pip install psutil &&
               /var/lib/awx/venv/my-custom-venv/bin/pip install -U "ansible == X.Y.Z" &&
               /var/lib/awx/venv/my-custom-venv/bin/pip install -U custom-python-module
           volumeMounts:

requirements/requirements_ansible.in

@@ -38,7 +38,6 @@ netaddr
 ovirt-engine-sdk-python==4.2.4    # minimum set inside Ansible facts module requirements
 # AWX usage
 pexpect==4.6.0    # same as AWX requirement
-python-memcached==1.59    # same as AWX requirement
 psutil==5.4.3    # same as AWX requirement
 setuptools==36.0.1
 pip==9.0.1

requirements/requirements_ansible.txt

@@ -91,7 +91,6 @@ pynacl==1.2.1             # via paramiko
 pyopenssl==17.5.0         # via azure-cli-core, pyvmomi, requests-credssp
 pyparsing==2.2.0          # via packaging
 python-dateutil==2.6.1    # via adal, azure-storage, botocore
-python-memcached==1.59
 pyvmomi==6.5
 pywinrm[kerberos]==0.3.0
 pyyaml==3.12              # via azure-cli-core, knack, openstacksdk, os-client-config
@@ -105,7 +104,7 @@ s3transfer==0.1.13        # via boto3
 secretstorage==2.3.1      # via keyring
 selectors2==2.0.1         # via ncclient
 shade==1.27.0
-six==1.11.0               # via azure-cli-core, bcrypt, cryptography, isodate, keystoneauth1, knack, munch, ncclient, ntlm-auth, openstacksdk, ovirt-engine-sdk-python, packaging, pynacl, pyopenssl, python-dateutil, python-memcached, pyvmomi, pywinrm, stevedore
+six==1.11.0               # via azure-cli-core, bcrypt, cryptography, isodate, keystoneauth1, knack, munch, ncclient, ntlm-auth, openstacksdk, ovirt-engine-sdk-python, packaging, pynacl, pyopenssl, python-dateutil, pyvmomi, pywinrm, stevedore
 stevedore==1.28.0         # via keystoneauth1
 tabulate==0.7.7           # via azure-cli-core, knack
 urllib3==1.24             # via requests