Add support for ebs volumes
Add tag support for resources where this information is not available
with the Enum method (ELB for instance)

To achieve this:
*addition of a tags_spec Meta property with the method to
retrieve tags and the jmespath
*Modification of the tags methods in the AWSResource class
Adding MetricData class.
Update unit tests to be aware of MetricData return value.
Merge pull request #28 from garnaat/add-metric-data

Adding MetricData class.
Add parent property to volumes (id of instance it is attached to
    or None if not attached)
Add simple tests for volume resource
Add unit testing for loadbalancers including the retrieval of tags
through the tags_specs property
Merge pull request #29 from lbernail/develop

Support for EBS volumes and tags for resources where describe methods is not sufficient
Adding support for Route53 HealthChecks
Merge pull request #31 from garnaat/add-health-checks

Adding support for Route53 HealthChecks
Fixing some small PEP8 formatting issues.
Merge pull request #32 from garnaat/pep8-tweaks

Fixing some small PEP8 formatting issues.
Adding support for RDS tags which are handled completely differently than other tags and, thus, required changes to tags_spec.  Also added some tests.
Merge pull request #33 from garnaat/rds-tagging

Adding support for RDS tags
bumping version number
Merging
removing newline