Replace signer and query api

Signed-off-by: Boyan Dimitrov <boyan.dimitrov@hailocab.com>
Refactor autoscaling groups related methods and make them match more closely the AWS spec

Signed-off-by: Boyan Dimitrov <boyan.dimitrov@hailocab.com>
Add more detailed unit tests

Signed-off-by: Boyan Dimitrov <boyan.dimitrov@hailocab.com>
Refactor LaunchConfiguration methods and error wrapping
Add DeleteNotificationConfiguration and DeleteTags plus more tests
Refactor DescribeLaunchConfigurations to match the spec and add tests
Refactor SetDesiredCapacity, SuspendProcesses, ResumeProcesses according to spec. Add tests
Update PutScheduledUpdateGroupAction and DescribeScheduledActions to match the spec and add tests
Add AttachInstances method and tests. Semantical code reordering
Add DescribeAccountLimits, DescribeAdjustmentTypes, DescribeAutoScalingInstances and related tests
Add DescribeAutoScalingNotificationTypes, DescribeMetricCollectionTypes and DescribeNotificationConfigurations methods and tests
Add DescribePolicies and DescribeScalingActivities plus tests. Add missing xml parser tags. Fix comments
int -> in64; 0 is perfectly valid value for asg size or capacity
Add DescribeTags, DescribeScalingProcessTypes and DescribeTerminationPolicyTypes and tests. Add EC2 Filters Support. Reorder DescribeScheduledActions.
Be more strict with params validation
Add DisableMetricColleciton, EnableMetricCollection, ExecutePolicy methods and tests
Add PutNotificationConfiguration, PutScalingPolicy, SetInstanceHealth methods and tests. Small reoredering
Add TerminateInstanceInAutoScalingGroup; Add more tests; Fix DescribeScheduledActions xml marshaler tags
Merge test responses in a single package; Get rid of the custom http server in favor of the goamz testutil suite
Delete the v2 signer - already replaced by v4