Add DML migration processing to spanner

[plemanach]

Hello,

This pull request add DML migration support for spanner #135.

Thanks,

Patrice

[coveralls]

coverage: 58.683% (+0.2%) from 58.526%
when pulling 325ee0b on plemanach:master
into 856ea12 on golang-migrate:master.

[ACopelandTakeoff]

Any update on this PR? This would be an awesome feature to have.

[benjih]

I have just tested @plemanach's branch against a codebase I am working on that required support for DML and can confirm that this change worked for me!

@dhui Is this something that can be merged in?

[ElmosHomie492]

Is there an update on this? I would definitely love the ability to run DML queries using this.

[krak3n]

What do we need to do to get this merged?

[jtwatson]

@dhui Is there anything we can do to help get this merged?

This would be an awesome feature to have for spanner!

[calvinbrown085]

@dhui What can we do to get this branch merged? Is there anything I can help with?

[jha-ramesh]

@dhui @Fontinalis , is there anything that we can do to expedite the merging of this branch ? This is much needed functionality that other supported databases already have

[calvinbrown085]

@dhui @mattes @dimag-jfrog @kmuratov @taywrobel

Figured i'd ping the masses here, i'd love it if we can get this PR moving, is there any way I can help here? It looks like this project has been stale for a bit. We use this project a lot here at our company and i'd be happy to help spend some time to maintain it if that's preferable, please just let me know :)