Fix GitHub Actions (TartanLlama#163)

* Update cmake.yml

* Update cmake.yml

* Update cmake.yml

* Update cmake.yml

* Update cmake.yml

* Update cmake.yml

* Update cmake.yml

Author: TartanLlama

.github/workflows/cmake.yml

@@ -2,7 +2,7 @@ name: CMake
 
 on:
   push:
-    branches: [ "master" ]
+    branches: [ "master", "actions" ]
   pull_request:
     branches: [ "master" ]
 
@@ -112,10 +112,15 @@ jobs:
 
     - name: Setup Toolchain
       run: |
+        sudo apt-add-repository 'deb http://azure.archive.ubuntu.com/ubuntu/ focal main'
+        sudo apt-add-repository 'deb http://azure.archive.ubuntu.com/ubuntu/ focal universe'  
         sudo apt-add-repository 'deb http://azure.archive.ubuntu.com/ubuntu/ xenial main'
         sudo apt-add-repository 'deb http://azure.archive.ubuntu.com/ubuntu/ xenial universe'  
         sudo apt-add-repository 'deb http://azure.archive.ubuntu.com/ubuntu/ bionic main'
         sudo apt-add-repository 'deb http://azure.archive.ubuntu.com/ubuntu/ bionic universe'
+        sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test
+        
+        sudo apt update
         ${{matrix.install}}
 
     - name: Configure CMake