Fixes compute error

We observed a compute error in  the tests due to a change
(# I94f5af2055d1b6b41a9a170ca9b4daf57363c972) increasing
the disk to 20 GB in production. This will set it for tests
back to 3 GB which should avoid the gates failing on disk
failure.

We also observed a pip error and I think it should be fixed
with If2f1ab03ccd9400fe05e2948ddfe33c8796dbd97 - so
make tye pip install become: true to work around this
until the other patch merges.

Change-Id: I31b6c5d20cedb0df6648925566afd312d7f1dda9

tasks/octavia_certs_install.yml

@@ -21,6 +21,7 @@
       {{ 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('') }}
+  become: true
 
 - name: Generate Cert Dirs
   file:

tests/os_octavia-overrides.yml

@@ -22,6 +22,10 @@ test_octavia_amphora: True
 octavia_v2: True
 octavia_v1: False
 
+# Infra hosts don't have enough disk for the 20 GB
+# introduced by Change # I94f5af2055d1b6b41a9a170ca9b4daf57363c972
+octavia_amp_disk: 3
+
 test_octavia_api_host: "{{ hostvars['octavia1']['ansible_host'] }}"
 
 ## octavia User / Group