Add cert for gem signing.

certs/will_in_wi.pem

@@ -0,0 +1,21 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

letsencrypt_webfaction.gemspec

@@ -24,6 +24,9 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = %w(lib)
 
+  spec.cert_chain  = ['certs/will_in_wi.pem']
+  spec.signing_key = File.expand_path('~/.ssh/gem-private_key.pem') if $0 =~ /gem\z/
+
   spec.required_ruby_version = '>= 2.1.0'
 
   spec.add_runtime_dependency 'acme-client', '~> 0.3.0'