run CI on 1.6 and 1.7

Author: vchuravy

.github/workflows/ci.yml

@@ -17,7 +17,8 @@ jobs:
           - "1.3"
           - "1.4"
           - "1.5"
-          - "^1.6.0-0"
+          - "1.6"
+          - "1.7"
           - "nightly"
         os:
           - ubuntu-latest