add travis ci

chore: added toggle axis in user doc
chore: updated big brain origin dataset
bugfix: encode uri for dataset preview

chore: reworked how fixedmousecontexualcontainer works
chore added unit and e2e for fixedMouseCxt
tweak: by default layerbrowser is now collapsed
tweak: reduced region name in ctx menu
chore: removed unused import

chore: fixed draggable dataset preview

chore: removed repeating code
feat: added dev banner
chore: removed unused css

chore: clean up unused css

rc jugex coming soon, active selection encoding, ngViewerState, hover tooltip for tabs, jubrian pmap attribution, data window no longer duplicates, databrowser truncate name, MVP ng layer control