allow wasabi 4.x, rubygems mfa, default ruby devcontainer config

.devcontainer/devcontainer.json

@@ -0,0 +1,22 @@
+// For format details, see https://aka.ms/devcontainer.json. For config options, see the
+// README at: https://github.com/devcontainers/templates/tree/main/src/ruby
+{
+	"name": "Ruby",
+	// Or use a Dockerfile or Docker Compose file. More info: https://containers.dev/guide/dockerfile
+	"image": "mcr.microsoft.com/devcontainers/ruby:0-3-bullseye"
+
+	// Features to add to the dev container. More info: https://containers.dev/features.
+	// "features": {},
+
+	// Use 'forwardPorts' to make a list of ports inside the container available locally.
+	// "forwardPorts": [],
+
+	// Use 'postCreateCommand' to run commands after the container is created.
+	// "postCreateCommand": "ruby --version",
+
+	// Configure tool-specific properties.
+	// "customizations": {},
+
+	// Uncomment to connect as root instead. More info: https://aka.ms/dev-containers-non-root.
+	// "remoteUser": "root"
+}

savon.gemspec

@@ -18,7 +18,7 @@ Gem::Specification.new do |s|
 
   s.add_dependency "nori",     "~> 2.4"
   s.add_dependency "httpi",    ">= 2.4.5"
-  s.add_dependency "wasabi",   "~> 3.4"
+  s.add_dependency "wasabi",   ">= 3.4"
   s.add_dependency "akami",    "~> 1.2"
   s.add_dependency "gyoku",    "~> 1.2"
   s.add_dependency "builder",  ">= 2.1.2"
@@ -34,6 +34,8 @@ Gem::Specification.new do |s|
   s.add_development_dependency "mocha", "~> 0.14"
   s.add_development_dependency "json",  ">= 2.3.0"
 
+  s.metadata["rubygems_mfa_required"] = "true"
+
   s.files = Dir['CHANGELOG.md', 'LICENSE', 'README.md', 'Rakefile', 'lib/**/*.rb']
 
   s.require_path = "lib"