Adds constraints to all pip installs

Recently we ran into trouble with the cmd2 extension's
latest version being python3 only. This exposed the need
to constrain all pip installs (as it should have been)

Change-Id: I8f27bddd45905c14bec486c515b5b190c66eaf20

tasks/octavia_certs_install.yml

@@ -17,6 +17,10 @@
   pip:
     name: pyOpenSSL
     state: present
+    extra_args: >-
+      {{ octavia_developer_mode | ternary(pip_install_developer_constraints | default('--constraint /opt/developer-pip-constraints.txt'), '') }}
+      {{ (pip_install_upper_constraints is defined) | ternary('--constraint ' + pip_install_upper_constraints | default(''),'') }}
+      {{ pip_install_options | default('') }}
 
 - name: Generate Cert Dirs
   file:

tests/test-configure-octavia.yml

@@ -22,6 +22,10 @@
       pip:
         name: "shade"
         state: "{{ octavia_pip_package_state }}"
+        extra_args: >-
+          {{ octavia_developer_mode | ternary(pip_install_developer_constraints | default('--constraint /opt/developer-pip-constraints.txt'), '') }}
+          {{ (pip_install_upper_constraints is defined) | ternary('--constraint ' + pip_install_upper_constraints | default(''),'') }}
+          {{ pip_install_options | default('') }}
       register: install_packages
       until: install_packages|success
       retries: 5

tests/test-octavia.yml

@@ -37,6 +37,10 @@
       pip:
         name: "{{ item }}"
         state: "{{ octavia_pip_package_state }}"
+        extra_args: >-
+          {{ octavia_developer_mode | ternary(pip_install_developer_constraints | default('--constraint /opt/developer-pip-constraints.txt'), '') }}
+          {{ (pip_install_upper_constraints is defined) | ternary('--constraint ' + pip_install_upper_constraints | default(''),'') }}
+          {{ pip_install_options | default('') }}
       register: install_packages
       until: install_packages|success
       retries: 5
@@ -47,6 +51,7 @@
         - "shade"
         - "python-octaviaclient"
         - "python-openstackclient"
+        - "cmd2<0.9.0" # >=0.9.0 is python3 only
 
     - name: Ensure public network exists
       os_network: