Merge pull request #92 from yext/master

Add support for deleting route53 hosted zone
Create RDS package
Add RDS endpoints, and signing version
remove package comment (squash me)
Add very basic describe db instances method, and generic query / service structure
Merge pull request #93 from yext/master

Complete DescribeTable and allow name as input
Add initial RDS types, there are a lot of these... :cold_sweat:
Initial generic signing with v4
Correct VpcSecurityGroup to VpcSecurityGroupMembership
Implement more types (just for DBInstance) and fix xml mappings
Order types alphabetically
Implement PendingModifiedValues type
Add more RDS types
Option configuration type
Add OptionSetting and Parameter types
Implement final RDS types :boom:
Update RDS types with descriptions and shorten all the doc urls
Switch RDS to V2 Signature, will upgrade this separately
Fix import
Pull out API version into a const