Fix deep merging issue.

Should not be partial application of the extractor function, but an
actual extractor!
Merge pull request #327 from mattdenner/fix_deep_merge_issue

Fix deep merge issue
Change #dropzone ids to classes
Remove messy inline style stub from markup
Change rack scan view to use .dropzone over #dropzone
Lint rack_scan_view
Merge branch 'fix_vol_check_dropzone' into development
2 More #dropzones fixed
Merge branch 'development' of https://github.com/sanger/s2_extraction_pipeline into development
Changes css selector to li element in selection_page_controller for referring correctly
to the input of the labware to be scanned.
Hide the text aliquot type until solved correctly