Add code coverage reporting

* add simplecov dev dependency
* load simplecov in spec_helper
* fail the tests if coverage drops
* ignore coverage dir

Closes #7
Closes #9

Author: llimllib

.gitignore

@@ -13,3 +13,5 @@ Gemfile.lock
 docs/_build/
 
 pkg
+
+coverage

connect_vbms.gemspec

@@ -30,6 +30,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "rake", "~> 10.0"
   spec.add_development_dependency "rspec", "~> 3.3"
   spec.add_development_dependency "equivalent-xml", "~> 0.6"
+  spec.add_development_dependency "simplecov", "~> 0.10"
 
   spec.add_runtime_dependency "httpi", "~> 2.4"
   spec.add_runtime_dependency "nokogiri", "~> 1.6"

spec/spec_helper.rb

@@ -1,4 +1,8 @@
 # encoding: utf-8
+require 'simplecov'
+SimpleCov.start do
+    refuse_coverage_drop
+end
 
 # TODO: remove this once we can put our source code in `lib/`
 $LOAD_PATH << File.join(File.dirname(__FILE__), "..", "src")