(maint) Move testing matrix to files on disk

Prior to this commit, the PR acceptance jobs would echo the matrix from
within the workflow. This commit moves the matrix lists to files in the
fixtures directory to make it easier to automate updates.

Author: Jarret Lavallee

.github/workflows/pe_latest_testing.yml

@@ -53,7 +53,7 @@ jobs:
     - name: Setup Acceptance Test Matrix
       id: get-matrix
       run: |
-          echo  "::set-output name=matrix::{\"platforms\":[{\"label\":\"CentOS-7\",\"provider\":\"provision::provision_service\",\"image\":\"centos-7\"},{\"label\":\"CentOS-8\",\"provider\":\"provision::provision_service\",\"image\":\"centos-8\"},{\"label\":\"RedHat-7\",\"provider\":\"provision::provision_service\",\"image\":\"rhel-7\"},{\"label\":\"Ubuntu-1804\",\"provider\":\"provision::provision_service\",\"image\":\"ubuntu-1804-lts\"},{\"label\":\"RedHat-8\",\"provider\":\"provision::provision_service\",\"image\":\"rhel-8\"},{\"label\":\"Sles-12\",\"provider\":\"provision::provision_service\",\"image\":\"sles-12\"}],\"collection\":[\"2021.2.0\"]}"
+          echo  "::set-output name=matrix::$(cat spec/fixtures/matrix/latest.json)"
     - name: "Honeycomb: Record Setup Test Matrix time"
       if: ${{ always() }}
       run: |

.github/workflows/pe_lts_testing.yml

@@ -53,7 +53,7 @@ jobs:
     - name: Setup Acceptance Test Matrix
       id: get-matrix
       run: |
-          echo  "::set-output name=matrix::{\"platforms\":[{\"label\":\"CentOS-7\",\"provider\":\"provision::provision_service\",\"image\":\"centos-7\"},{\"label\":\"CentOS-8\",\"provider\":\"provision::provision_service\",\"image\":\"centos-8\"},{\"label\":\"RedHat-7\",\"provider\":\"provision::provision_service\",\"image\":\"rhel-7\"},{\"label\":\"Ubuntu-1804\",\"provider\":\"provision::provision_service\",\"image\":\"ubuntu-1804-lts\"},{\"label\":\"RedHat-8\",\"provider\":\"provision::provision_service\",\"image\":\"rhel-8\"},{\"label\":\"Sles-12\",\"provider\":\"provision::provision_service\",\"image\":\"sles-12\"}],\"collection\":[\"2019.8.7\"]}"
+          echo  "::set-output name=matrix::$(cat spec/fixtures/matrix/lts.json)"
     - name: "Honeycomb: Record Setup Test Matrix time"
       if: ${{ always() }}
       run: |

spec/fixtures/matrix/latest.json

@@ -0,0 +1 @@
+{"platforms":[{"label":"CentOS-7","provider":"provision::provision_service","image":"centos-7"},{"label":"CentOS-8","provider":"provision::provision_service","image":"centos-8"},{"label":"RedHat-7","provider":"provision::provision_service","image":"rhel-7"},{"label":"Ubuntu-1804","provider":"provision::provision_service","image":"ubuntu-1804-lts"},{"label":"RedHat-8","provider":"provision::provision_service","image":"rhel-8"},{"label":"Sles-12","provider":"provision::provision_service","image":"sles-12"}],"collection":["2021.2.0"]}

spec/fixtures/matrix/lts.json

@@ -0,0 +1 @@
+{"platforms":[{"label":"CentOS-7","provider":"provision::provision_service","image":"centos-7"},{"label":"CentOS-8","provider":"provision::provision_service","image":"centos-8"},{"label":"RedHat-7","provider":"provision::provision_service","image":"rhel-7"},{"label":"Ubuntu-1804","provider":"provision::provision_service","image":"ubuntu-1804-lts"},{"label":"RedHat-8","provider":"provision::provision_service","image":"rhel-8"},{"label":"Sles-12","provider":"provision::provision_service","image":"sles-12"}],"collection":["2019.8.7"]}