Remove Ruby 2.6 and 2.7

Author: jeremycole

.github/workflows/rspec.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: ["2.6", "2.7", "3.0", "3.1"]
+        ruby-version: ["3.0", "3.1"]
     steps:
     - uses: actions/checkout@v2
     - name: Set up Ruby

.github/workflows/rubocop.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: ["2.6", "2.7", "3.0", "3.1"]
+        ruby-version: ["3.0", "3.1"]
     steps:
       - uses: actions/checkout@v2
       - name: Set up Ruby