RFC - DO NOT MERGE - Run integration tests on travis ci

[lucafavatella]

Depends on #315.

Integration tests appear to fail on plain Riak provided by Travis CI.

• Does anyone have a script for checking or enforcing preconditions on Riak for the test to pass?
• Is anyone willing to investigate the failure and to progress on getting the integration tests run and pass on Travis CI? (I do not plan to.)

[lucafavatella]

Copying first failure only from Travis CI:

    riakc_pb_socket_tests:867: integration_tests (create a search index / get / list / delete with default timeout)...*failed*
in function riakc_pb_socket_tests:'-integration_tests/0-fun-147-'/2 (test/riakc_pb_socket_tests.erl, line 892)
in call from riakc_pb_socket_tests:'-integration_tests/0-fun-149-'/0 (test/riakc_pb_socket_tests.erl, line 889)
**error:{assertEqual,[{module,riakc_pb_socket_tests},
              {line,892},
              {expression,"riakc_pb_socket : list_search_indexes ( Pid )"},
              {expected,{ok,[[{index,<<"indextest">>},
                              {schema,<<"_yz_default">>},
                              {n_val,2}]]}},
              {value,{ok,[]}}]}
  output:<<"">>

[lukebakken]

The riak-erlang-client repository has a submodule that points to this repo:

https://github.com/basho/riak-client-tools/

Scripts in riak-client-tools are used by Basho's internal build system to set up Riak to do integration tests. Since these tests are run internally we have not pursued integration tests on Travis CI.

The Makefile used by the internal build system is here:

https://github.com/basho/riak-erlang-client/blob/develop/buildbot/Makefile