add vcr gem, add test helper script for running specific lines

script/testing/dtest

@@ -0,0 +1,23 @@
+#!/usr/bin/env ruby
+
+file, line = ARGV[0], nil
+test_name_pattern = nil
+
+if file =~ /:\d+/
+  file, line = file.split(/:/)
+end
+
+if line
+  text = File.read(file).split(/\r\n|\r|\n/)[line.to_i - 1]
+  if text =~ /(?:context|should) ["'](.+?)["']/
+    test_name_pattern = Regexp.escape($1)
+  end
+end
+
+env_options = {
+  "TEST" => file
+}
+
+env_options["TESTOPTS"] = "--name='/#{test_name_pattern}/'" if test_name_pattern
+
+exec(env_options, "bundle exec rake test")