test on nightly

Author: nhz2

.github/workflows/ci.yml

@@ -29,6 +29,7 @@ jobs:
           - 'min'
           - 'lts'
           - '1'
+          - 'nightly'
         os:
           - ubuntu-latest
           - macOS-latest

.github/workflows/downstream.yml

@@ -36,7 +36,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        julia-version: ['1']
+        julia-version: ['1', 'nightly']
         os: [ubuntu-latest]
         package:
           - {repo: ApproxFunBase.jl, group: JuliaApproximation}