[#3] Implemented full conditional logic for MySql.
[#13] Implemented mongo conditional logic.
[#13] ElasticSearch full conditional logic not implemented.
[#13] Fixed Elvis comments.
[#13] Added Elvis config file.
[#13] Changes based on PR comments.
[#13] Erlang style operators.
Merge pull request #88 from inaka/jfacorro.13.full.conditional.logic

[Closes #13] Full conditional logic