IDE-972 update to tycho 0.21.0 from 0.18.1 to support Java 8 execution environment
IDE-972 downgrade to tycho 0.20.0 from 0.21.0
Tycho 0.20.0 still supports Java 8 execution environment
Tycho 0.21.0 is causing trouble with running ui-tests during Maven verify phase
IDE-972 increment parent POM version from 0.0.1 to 0.0.2