begin testing on ruby 3, drop support for 2.6

Author: dunn

.github/workflows/lint.yml

@@ -18,12 +18,12 @@ jobs:
         uses: actions/cache@v2.1.3
         with:
           path: vendor/bundle
-          key: 2.6.5
+          key: 2.7.8
 
       - name: Setup Ruby
         uses: ruby/setup-ruby@v1.59.1
         with:
-          ruby-version: 2.6.5
+          ruby-version: 2.7.8
 
       - name: Install dependencies
         run: |

.github/workflows/test.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby: ['2.6', '2.7'] # TODO add 3.0 compat , '3.0']
+        ruby: ['2.7', '3.0']
     name: Run specs with ruby ${{ matrix.ruby }}
     steps:
       - uses: actions/checkout@v2

README.md

@@ -182,7 +182,7 @@ Once your the exporter has run, a download icon will appear on the exporters men
 
 ## Compatibility
 
-* Ruby 2.6 or 2.7 is required
+* Ruby 2.7 or newer is required
 * Hyrax 2.3 or newer is required
 
 ## Contributing