chore(build): Add bundle-audit to build

Author: bethesque

.travis.yml

@@ -18,3 +18,4 @@ before_script:
   - mysql -e 'CREATE DATABASE pact_broker;'
 script:
   - bundle exec rake
+  - bundle exec bundle-audit update && bundle exec bundle-audit

pact_broker.gemspec

@@ -39,6 +39,7 @@ Gem::Specification.new do |gem|
   gem.add_runtime_dependency 'rack-protection', '~>1.5'
   gem.add_runtime_dependency 'dry-types', '~> 0.10.3' # https://travis-ci.org/pact-foundation/pact_broker/jobs/249448621
 
+  gem.add_development_dependency 'bundler-audit', '~>0.4'
   gem.add_development_dependency 'sqlite3'
   gem.add_development_dependency 'pry-byebug'
   gem.add_development_dependency 'rake', '~>10.0'