Allows the redshift parameter group acceptance tests handle being ran in parallel better
```
$ make testacc TEST=./builtin/providers/aws TESTARGS='-run=TestAccAWSRedshiftParameterGroup_'
==> Checking that code complies with gofmt requirements...
go generate $(go list ./... | grep -v /terraform/vendor/)
2017/02/09 10:16:19 Generated command/internal_plugin_list.go
TF_ACC=1 go test ./builtin/providers/aws -v -run=TestAccAWSRedshiftParameterGroup_ -timeout 120m
=== RUN TestAccAWSRedshiftParameterGroup_importBasic
--- PASS: TestAccAWSRedshiftParameterGroup_importBasic (15.17s)
=== RUN TestAccAWSRedshiftParameterGroup_withParameters
--- PASS: TestAccAWSRedshiftParameterGroup_withParameters (13.16s)
=== RUN TestAccAWSRedshiftParameterGroup_withoutParameters
--- PASS: TestAccAWSRedshiftParameterGroup_withoutParameters (12.58s)
PASS
ok github.com/hashicorp/terraform/builtin/providers/aws 40.940s
```
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