Merge pull request #266 from rspec/add-3.0.0-rc1

Add 3.0.0-rc1

Author: JonRowe

ci/.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
     strategy:
       matrix:
         ruby:
-          - 3.0.0-preview2
+          - 3.0.0-rc1
           - 2.7
           - 2.6
           - 2.5