fixed embbeds one
preventing for when relation is nil or doesnt respond to metadata
Don't make embeds_one and empty array in the full_attributes when blank.
Add tests for embeds_one functionality.
Fix save(validate: false) not properly skipping validations.

This wasn't working since save! was being called in the before_save
callback, which was forcing validations on each save, regardless of the
options actually passed into save.
Remove Gemfile.lock and move development dependencies to the gemspec.
Merge branch 'embeds_one'
Merge branch 'save_options'

Conflicts:
	spec/support/models.rb