Remove 'ignore_errors: true' in favor of 'failed_when: false'

This change removes the use of 'ignore_errors: true' because it causes deployers
to see red output and a stacktrace, which traditionally means something is broken,
even when the failure is known to have a fall back option or be intentional. This
conversion will provide a generally cleaner interface.

It should be noted that the 'failed' filter will still function normally. Tasks
with the 'failed_when: false' option will still be marked as 'failed' in any
registered variable. This change simply makes the output look cleaner.

Change-Id: Iab6a4e4be29ae358cc95d94eb1090a7963a925df
Closes-Bug: #1633438
Signed-off-by: Kevin Carter <kevin.carter@rackspace.com>

tasks/install_offline.yml

@@ -22,7 +22,7 @@
     validate_certs: "{{ pip_validate_certs }}"
   register: get_pip_local
   until: get_pip_local | success
-  ignore_errors: True
+  failed_when: false
   retries: 5
   delay: 2
   run_once: yes

tasks/install_online.yml

@@ -21,7 +21,7 @@
     validate_certs: "{{ pip_validate_certs }}"
   register: get_pip
   until: get_pip | success
-  ignore_errors: True
+  failed_when: false
   retries: 5
   delay: 2
   tags:

tasks/install_source.yml

@@ -18,7 +18,7 @@
     python /opt/get-pip.py {{ pip_source_install_options }} \
                            {{ pip_get_pip_options }} \
                            {{ pip_packages | map('quote') | join (' ') }}
-  ignore_errors: true
+  failed_when: false
   register: pip_install
   until: pip_install | success
   retries: 3
@@ -40,7 +40,7 @@
     name: "{{ pip_required_pip_packages | map('quote') | join(' ') }}"
     state: latest
     extra_args: "{{ pip_install_options }}"
-  ignore_errors: true
+  failed_when: false
   register: install_packages
   until: install_packages | success
   retries: 5