[google|sql] Initial support for Google Cloud SQL

This commit adds the initial support for Google Cloud SQL:
- Adds a new service 'SQL' to the existing 'Google' provider
- Creates new shared methods to be reused by different services
- Add requests, models and tests for Tiers
[aws] add mock tagging for acls and vpcs, refactor types
add tagSet to describe_network_acls
pass tags when creating network acl
remove tag setting from describe_network_acls
apply tag filters to network acls
add tests for acl tag filtering
clean up acl test tag
update delete_tags request to match create_tags
add tagging for vpcs
move tagged_resources method to compute
Fix describe_internet_gateways calls for >1 igw

@internet_gateway was incorrectly reset after the first
InternetGatewaySet item.  On encountering a second, we end up
attempting to dereference nil as a hash, causing the parser to
blow up with an unintuitive error.
Merge pull request #3045 from jtopper/fix_describe_internet_gateways

Fix describe_internet_gateways calls for >1 igw
remove :host from request parameters, stopping excon errors.
Merge pull request #3046 from infovore/fix_elasticbeanstalk_excon_errors

remove :host from request parameters, stopping excon errors with Elastic Beanstalk
[glesys] API change, new attribute :bandwidth added
Merge pull request #3047 from barsoom/new_glesys_attribute

[glesys] API change, new attribute :bandwidth added
allow 1.8.7 failures

see also: #3048
[#3048] Lock down rest-client version

New versions have dropped 1.8.7 support and they are getting picked up
by Travis.
Merge pull request #3049 from fog/fix_187_dependencies

[Fixes #3048] Lock down rest-client version