Drop support for ruby 2.6 (#10)

Author: tcrouch

.github/workflows/gem-push.yml

@@ -14,10 +14,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    - name: Set up Ruby 2.6
+    - name: Set up Ruby 2.7
       uses: actions/setup-ruby@v1
       with:
-        ruby-version: 2.6.x
+        ruby-version: 2.7.x
 
     - name: Publish to GPR
       run: |

.github/workflows/ruby.yml

@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: ["2.6", "2.7", "3.0", "3.1"]
+        ruby-version: ["2.7", "3.0", "3.1"]
         allow-failure: [false]
         include:
           - ruby-version: "ruby-head"

.rubocop.yml

@@ -1,5 +1,5 @@
 AllCops:
-  TargetRubyVersion: 2.6
+  TargetRubyVersion: 2.7
 Metrics/AbcSize:
   Enabled: false
 Metrics/CyclomaticComplexity:

edits.gemspec

@@ -25,7 +25,7 @@ Gem::Specification.new do |spec|
   spec.bindir        = "exe"
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
-  spec.required_ruby_version = ">= 2.6"
+  spec.required_ruby_version = ">= 2.7"
 
   spec.add_development_dependency "benchmark-ips", "~> 2.8"
   spec.add_development_dependency "bundler", "~> 2.0"