Allows redshift security group tests to better handle being ran in parallel.
```
$ make testacc TEST=./builtin/providers/aws TESTARGS='-run=TestAccAWSRedshiftSecurityGroup_'
==> Checking that code complies with gofmt requirements...
go generate $(go list ./... | grep -v /terraform/vendor/)
2017/02/09 10:40:25 Generated command/internal_plugin_list.go
TF_ACC=1 go test ./builtin/providers/aws -v -run=TestAccAWSRedshiftSecurityGroup_ -timeout 120m
=== RUN TestAccAWSRedshiftSecurityGroup_importBasic
--- PASS: TestAccAWSRedshiftSecurityGroup_importBasic (12.98s)
=== RUN TestAccAWSRedshiftSecurityGroup_ingressCidr
--- PASS: TestAccAWSRedshiftSecurityGroup_ingressCidr (11.02s)
=== RUN TestAccAWSRedshiftSecurityGroup_updateIngressCidr
--- PASS: TestAccAWSRedshiftSecurityGroup_updateIngressCidr (32.81s)
=== RUN TestAccAWSRedshiftSecurityGroup_ingressSecurityGroup
--- PASS: TestAccAWSRedshiftSecurityGroup_ingressSecurityGroup (14.82s)
=== RUN TestAccAWSRedshiftSecurityGroup_updateIngressSecurityGroup
--- PASS: TestAccAWSRedshiftSecurityGroup_updateIngressSecurityGroup (37.43s)
PASS
ok github.com/hashicorp/terraform/builtin/providers/aws 109.090s
```
also removed the notion of tags from the redshift security group and
parameter group documentation until that has been implemented
Redshift Cluster CRUD and acceptance tests
Removing the Acceptance test for the Cluster Updates. You cannot delete
a cluster immediately after performing an operation on it. We would need
to add a lot of retry logic to the system to get this test to work
Adding some schema validation for RedShift cluster
Adding the last of the pieces of a first draft of the Redshift work - this is the documentation
Jake Champlin