Deprecate Ruby v2.6 since its life ended 14 months ago.

.github/workflows/pull-request.yml

@@ -7,7 +7,7 @@ jobs:
       matrix:
         os: [ubuntu-latest, macos-latest]
         # Due to https://github.com/actions/runner/issues/849, we have to use quotes for '3.0'
-        ruby: ['2.6', '2.6.9', '2.7', '3.0', '3.1', head]
+        ruby: ['2.7', '3.0', '3.1', head]
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v3

.rubocop.yml

@@ -1,5 +1,5 @@
 AllCops:
-  TargetRubyVersion: 2.6
+  TargetRubyVersion: 2.7
   NewCops: enable
 
 Style/StringLiterals:

arkana.gemspec

@@ -10,7 +10,7 @@ Gem::Specification.new do |spec|
   spec.license = "BSD-2-Clause"
   spec.summary = "Store your keys and secrets away from your source code. Designed for Android and iOS projects."
   spec.homepage = "https://github.com/rogerluan/arkana"
-  spec.required_ruby_version = ">= 2.6.9"
+  spec.required_ruby_version = ">= 2.7"
 
   spec.metadata["homepage_uri"] = spec.homepage
   spec.metadata["source_code_uri"] = "https://github.com/rogerluan/arkana"