Simplify pip install options

Using the omit template, we can now better control which pip options
we set.

Change-Id: I8a3abc0b623a75e1f695441f96b922a2a72e41f7
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

defaults/main.yaml

@@ -67,7 +67,10 @@ zuul_git_version: master
 
 zuul_install_method: git
 
-zuul_pip_version:
+zuul_pip_name: zuul
+#zuul_pip_extra_args:
+#zuul_pip_version:
+#zuul_pip_virtualenv:
 
 # tasks/service.yaml
 zuul_file_zuul_service_config_group: root

tasks/install/git.yaml

@@ -22,4 +22,6 @@
 - name: Pip install zuul from local git repo.
   become: yes
   pip:
+    extra_args: "{{ zuul_pip_extra_args|default(omit) }}"
     name: "file://{{ zuul_git_dest }}"
+    virtualenv: "{{ zuul_pip_virtualenv|default(omit) }}"

tasks/install/pip.yaml

@@ -15,12 +15,7 @@
 - name: Install zuul using pip.
   become: yes
   pip:
-    name: zuul
-  when: zuul_pip_version is none
-
-- name: Install zuul using pip.
-  become: yes
-  pip:
-    name: zuul
-    version: "{{ zuul_pip_version }}"
-  when: zuul_pip_version is not none
+    extra_args: "{{ zuul_pip_extra_args|default(omit) }}"
+    name: "{{ zuul_pip_name }}"
+    version: "{{ zuul_pip_version|default(omit) }}"
+    virtualenv: "{{ zuul_pip_virtualenv|default(omit) }}"