run CI on 1.6

Author: IanButterworth

.github/workflows/test.yml

@@ -14,8 +14,8 @@ jobs:
       fail-fast: false
       matrix:
         julia-version:
-          # - '1.6'
-          - 'nightly'
+          - '1.6'
+          # - 'nightly'
         julia-arch:
           - 'x64'
           - 'x86'