DRILL-6777: Setup CircleCI configs for Drill
- adding .circleci/config.yml to the project to launch CircleCI
- custom memory parameters
- usage of CircleCI machine
- excluding "SlowTest" and "UnlikelyTest" groups
- update maven version
- adding libaio.so library to solve MySQL integration tests
- update com.jcabi:jcabi-mysql-maven-plugin library version
- TODO descriptions for the future enhancements of CircleCI build for Drill
close apache/drill#1493
