intercept 404 on thumbnail with default thumbnail

intercept 404 on thumbnail with default thumbnail

Render default thumnail when thumbnail unavailable for any work

This commit with rescue 404 and 500 error with default thumbnail when trying to download thumbnail
Updating thumbnail display when no document

@TODO - The thumbnail display is an ugly partial. Ideally this logic
should be pushed to the downloads/thumbnail controller; Let the
controller deal with the image it received.

JIRA References:
https://jira.duraspace.org/browse/HYDRASIR-88
Merge pull request #504 from projecthydra/feature/HYDRASIR-88-Generic_thumbnails

HYDRASRI-88 intercept 404 on thumbnail with default thumbnail
Patching the Soft Delete monkey patch

[skip ci]
Merge pull request #506 from projecthydra/fix/soft-delete-install

Patching the Soft Delete monkey patch
Updating Article's metadata datastream

Matching Notre Dame's defined Metadata Application profile for
Article. See:

http://ndlib.github.io/metadata_application_profile/templates/

@WIP - This is a work in progress. The purpose of this commit is a
reference for updates against Article. This will impact the migration
scheme.

[skip ci]
Renaming :journal_information to :source

This appears to be the only required changes for user facing data.

[skip ci]
Removing identifier and date_digitized

[skip ci]
Rearranging the migration runner

[skip ci]
Adding initial migration script

[skip ci]
Writing transformer for metadata
Including MetadataNormalization cap task
Updating matchers to be discoverable

I want `require 'curate/spec_support'` to function in applications
that mount the Curate engine.

[skip ci]