DyTask scenario (#406)

Stubbed out scenario class and created unit test.
Add todos and refactor
Add missing header
Updated todo
Correct PMD unused field warning
#441 upgrade to jcabi-ssh 1.2.1
#441 removed redundant resources from src/test/resources/com/jcabi/ssh
#405 Implement memo method.

Added DyMemo and related test cases.
todo: implement update method
#459: Dynamo classes marked Immutable.
#442 moved DyBaseITCase to com.thindeck.dynamo
Use dynamo mocks in DyRepoTest#memo
Merge remote-tracking branch 'upstream/master' into 405
#417: add new repo test
#459 Fix after review.
#449: Fix after review

Command sed replaced with perl.
#449: Fix after review

Adding missing single quote.
#459 Fix after review.
Merge remote-tracking branch 'upstream/master' into 420
Merge remote branch 'fork/405'