updated github action (now it runs with ubuntu-latest)

Author: pwittchen

.github/workflows/build.yml

@@ -9,7 +9,7 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     strategy:
       matrix:
         python-version: ["3.6", "3.7"]

.github/workflows/deploy.yml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
     - name: checkout
       uses: actions/checkout@v3