add StorageType as an RDS option

[skippy]

First off, an apology. I'm not familiar with Go and I wasn't able to figure out how to compile and run the tests. I'll continue to bang away at it, but if you wanted to add a CONTRIBUTING.md document, that would be welcome :)

This PR is, in part, to address hashicorp/terraform#439. While I'm figuring out the build chain, I wanted to throw this over the fence. I hope you don't mind.

[davedash]

@skippy I'm new too, so here's what I did (in a similar issue #193):

cd rds
go get .../.
go test

The second command might have a few issues, but it install enough dependencies for the tests to work.

Let me know if this helps or not.

[josh-padnick]

I was looking for exactly this PR! Any chance this can get merged for the next version?

[skippy]

thanks @davedash ! That didn't work for me but I was able to sort of get it testing, I think (within docker golang:1.4). Yet the test is failing with:

# _/usr/src/myapp/rds_test
./rds_test.go:51: unknown rds.CreateDBInstance field 'StorageType' in struct literal
FAIL    _/usr/src/myapp/rds [build failed]

I'm sure I'm going to have egg on my face in no time as this is a n00b mistake. But I just don't see it... makes me wonder if I'm testing against the wrong rds.go file? damn.

[mitchellh]

Done by #215 sorry I saw that first!