updates manage LWRP to support single PEM file
v0.5.0

* ChefSpec create_certificate_manage matcher added

TODO: tests, of course
Merge branch 'add-combined-file-option' of github.com:orgsync-cookbooks/cookbook-certificate into orgsync-cookbooks-add-combined-file-option
v0.5.0

* ChefSpec create_certificate_manage matcher added.
* Added combined_file resource.
* Update build files.
* Added Rubocop.
* Added BATS tests.