Merge pull request #1103 from dandi/upgrade-ubuntu

Update test.yml to use ubuntu-latest

Author: yarikoptic

.github/workflows/test.yml

@@ -25,7 +25,7 @@ jobs:
       matrix:
         os:
           - windows-2019
-          - ubuntu-18.04
+          - ubuntu-latest
           - macos-latest
         python:
           - 3.7
@@ -35,10 +35,10 @@ jobs:
         mode:
           - normal
         include:
-          - os: ubuntu-18.04
+          - os: ubuntu-latest
             python: 3.7
             mode: dandi-api
-          - os: ubuntu-18.04
+          - os: ubuntu-latest
             python: 3.7
             mode: dev-deps
         exclude: