tests for oracle
updated phpunit.xml to bypass oracle tests by default
renamed oracle test case
findFirst + full oracle support + reorganizing tests

- redsql can select only a list of fields instead of "*"
- introduced Finder::findFirst as an option to Finder::find
- finally full oracle support
- organizing phpunit tets in groups
- updated travis to execute tests on travis @group only

TODO

- get ready for version 0.1.12 launch
- turn WHERE into a filter like all other clauses