Add 'yaml.parser' and 'yaml.dumper' services.
Merge pull request #6 from v3kwip/yaml-services

Add 'yaml.parser' and 'yaml.dumper' services
Reduce number of Travis builds.
Merge branch '7.x-1.x' into routing

* 7.x-1.x:
  Reduce number of Travis builds.
  Add 'yaml.parser' and 'yaml.dumper' services.