Test on Ruby 2.6 and set as minimum Ruby version

Author: spohlenz

.github/workflows/rspec.yml

@@ -7,9 +7,11 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        gemfile: [ rails-6.0, rails-6.1 ]
-        ruby: [ '2.7' ]
         include:
+          - gemfile: rails-6.0
+            ruby: '2.6'
+          - gemfile: rails-6.1
+            ruby: '2.6'
           - gemfile: rails-6.1
             ruby: '3.0'
           - gemfile: rails-7.0

trestle-auth.gemspec

@@ -16,7 +16,7 @@ Gem::Specification.new do |spec|
 
   spec.require_paths = ["lib"]
 
-  spec.required_ruby_version = Gem::Requirement.new(">= 2.3.0")
+  spec.required_ruby_version = Gem::Requirement.new(">= 2.6.0")
 
   spec.metadata["homepage_uri"] = spec.homepage
   spec.metadata["source_code_uri"] = "https://github.com/TrestleAdmin/trestle-auth"