feat: automate install of zhmc dependencies (#86)

Automatically install ibm.ibm_zhmc collection's python package
dependencies, and update docs to match.

Signed-off-by: Jacob Emery <jacob.emery@ibm.com>

docs/prerequisites.md

@@ -46,9 +46,6 @@ ansible-galaxy collection install community.general community.crypto ansible.pos
 ```
 * If you will be using these playbooks to automate the creation of the LPAR(s) that will act as KVM host(s) for the cluster, you will also need:
 ```
-pip3 install zhmcclient cryptography packaging PyYAML
-```
-```
 ansible-galaxy collection install ibm.ibm_zhmc 
 ```
 * If you are using MacOS, you also need to have [Homebrew](https://brew.sh/) package manager installed:

playbooks/1_create_lpar.yaml

@@ -6,6 +6,16 @@
   vars_files: 
     - "{{ inventory_dir }}/group_vars/all.yaml"
   tasks:
+    - name: Install required python packages.
+      ansible.builtin.pip:
+        name: "{{ item }}"
+      loop:
+        - requests
+        - zhmcclient
+        - cryptography
+        - packaging 
+        - PyYAML
+
     - name: Include vars for first LPAR if it is to be created.
       include_vars:
         file: "{{ inventory_dir }}/host_vars/{{ env.z.lpar1.hostname }}.yaml"