Add tests for Riak security for HTTP and PB endpoints

[Vagabond]

Tests don't cover the complete API, but they are the most comprehensive erlang client tests we have. I'm hoping the other client libraries can more completely cover the Riak API with security enabled, because I'm sick of writing client tests ;)

These tests should run against all backends

See also basho/riak#355.

[seancribbs]

This should probably use rt:connection_info()

[seancribbs]

Do I have to generate certs/etc for these tests? When running them I get:

14:42:24.412 [error] SSL: certify: ssl_handshake.erl:1155:Fatal error: unknown ca

[Vagabond]

The test intentionally tries invalid CAs, those should not cause the test to fail...

[seancribbs]

My notes from getting these tests to run:

1. R16 introduced an additional wrapper around the <<"unknown ca">> error message, so it appears like {tls_alert, <<"unknown ca">>}. This should be fixed in the test (requiring R16+), or wrapped in a macro with some version-switching.
2. I had to manually apply Retry requests when the worker has the connection close cmullaparthi/ibrowse#100 to ibrowse in order to get the list-buckets step in the http test not to timeout.
3. Some more logging in the progress of the test would help identify what is being tested and where specific errors or failures occur, but that's not required for these tests to pass.
4. The counter tests fail as expected, I had to comment them out to complete the test.

[seancribbs]

👍 with the provisos listed (ibrowse patch, counters fail), works like a champ