Bump minimal ruby version to 2.4

Author: flash-gordon

dry-auto_inject.gemspec

@@ -19,7 +19,7 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ['lib']
 
-  spec.required_ruby_version = '>= 2.3.0'
+  spec.required_ruby_version = '>= 2.4.0'
 
   spec.add_runtime_dependency 'dry-container', '>= 0.3.4'