fix for https://github.com/splunk/splunk-sdk-ruby/issues/28

[fornellas]

This should raise exceptions when error / fatal messages are sent by the API.

[shakeelmohamed]

Hi @fornellas,

Thanks for doing this work, and submitting the contributor agreement!
Can you make a new PR against the develop branch?
If possible, can you write a test to reproduce the issue from #28?

[fornellas]

Did you review the code? Would this be the best solution? If so, I'll try to write some tests.

[shakeelmohamed]

@fornellas The changes look reasonable, tests would be even better! We won't merge directly into the master branch though, so you will need to make a new PR.

[itay]

@fornellas thanks for submitting this. Would you mind:

1. Rebasing your branch against develop
2. Adding tests
3. Changing the PR to target develop

[TigerWolf]

Any progress on this?

[fornellas]

I have not had time to learn Test::Unit and build a proper test, I solved my issue here by monkey patching the solution in my application code for now.