make code compatible with mongo ruby driver >= 2.0.0

[thikonom]

I made some changes to make the code compatible with the new version of the mongo driver (>= 2.0.0).

[coreypobrien]

This needs to be /^E11000/

Here's a snippet of the error: :exception=>#<Mongo::Error::OperationFailure: E11000 duplicate key error...

[coreypobrien]

+1 after the fix for the duplicate key error
I upgraded my mongo driver which hit this bug and caused everything to stop working. This patch got everything back normal.

[thikonom]

@coreypobrien thanks for spotting the typo. I'm confused does it work for you or not ?

[coreypobrien]

Yeah it works for me except for the duplicate record error which just sends things into an infinite loop of retry hell :) Sorry about the confusing comment. I edited it to be clearer

[thikonom]

No worries mate.
I amended the regex, should be fine now.

[coreypobrien]

This fixes #3 so we can keep using the latest mongo driver. There is also #8 which pegs the driver to an older version. I'd prefer this fix.

[purbon]

Thanks a lot for your contribution @thikonom. To be able to go forward with this PR it would be necessary that you sign the CLA (https://www.elastic.co/contributor-agreement).

Looking forward to get this in,

• purbon

[thikonom]

Hey @purbon, I just signed it.

[purbon]

thanks a lot @thikonom, I just merged this PR with #14 where I will focus on bringing this changes all in including adding unit test to the plugin, so I will close this PR for now. Thanks a lot man! much appreciate your contribution.