Fix display name inconsistencies in java-datetime Test

[c-guntur]

Fix the DateTimeKataDisplayNames to drop the "verify" from the JUnit output. Fix the none.cvg.datetime.DateTimeKataDisplayNames#generateDisplayNameForMethod() to render text from substring after 'verify'. See similar example at: none.cvg.handles.HandlesKataDisplayNames#generateDisplayNameForMethod in java-handles.

[marouaneunix]

PR: https://github.com/c-guntur/java-katas/pull/28