Scroll to element implemented for ↑ and ↓ directions.
Fixtures updated and new test case added.
Element renamed as container for better semantic.
Code documentation added.
Focus method renamed to scrollTo.
Test case created for inContainerViewport method.
Test case created for inContainerViewport method. Fixes #5.
Merge branch 'feature-scroll-to-element' into develop
v1.0.1 prepared.