This includes:
- updates to Gemfile and lock
- rake task tweaks to allow rake to run
- `rails generate blacklight:install`
- `rails generate blacklight:models`
- `rake db:migrate`

Now we watch all the tests break and start fixing stuff.

Also the namespace of the extensions changed.

Generated rails_helper.  Folded in distinct pieces of spec_helper and
changed .rspec file to require rails_helper now.

Remove outmoded include statements:
- `bootstrap-responsive` not separate now, release notes for 5.0.0 say
  [remove
  it](https://github.com/projectblacklight/blacklight/releases/tag/v5.0.0),
- `blacklight/responsive` seems to disappear with it,
- `improved-modal/bootstrap-modal` not required in bootstrap 3.

- catalog_index_path is now search_catalog_path
- catalog_facet_path is now facet_catalog_path
- catalog_path is now solr_document_path
- citation_catalog_path is now citation_solr_document_path

Rake file moved: it has general purpose bassi tasks in it, not just ci.

- Require Oracle JDK 8
- Ruby 2.3.1 or bust

Dev and Stage servers are already upgraded.  Prod is waiting on
completion of upgrades, but will be 2.3.1 at next deploy.

This is now separate from each core `conf`.

Error was:
```
ERROR: Error CREATEing SolrCore 'blacklight-core': Unable to create core
[blacklight-core] Caused by: org.apache.solr.handler.admin.AdminHandlers
```

The render call takes `@document` as its first argument.  H4 appears to
be default, therefore unnecessary to pass.

The two tests still fail, but now they fail at the same point as the rest,
instead of ahead of it.

From http://getbootstrap.com/migration/#classes

Warning was:
```
DEPRECATION WARNING: num_pages is deprecated and will be removed in
Kaminari 1.0. Please use total_pages instead.
```

Added a second set of tests to check that locale-setting works
correctly.

Error was, for example:
```
Sprockets::FileNotFound:
 couldn't find file 'bootstrap-carousel'
```

Deprecated in 4.x, removed in current BL.

See:
projectblacklight/blacklight@34c450b#diff-1948ff0d97b888dc61ae381aec62dfa5L68

Note this disables some styling that no longer has the underlying
mix-ins.  This should affect appearance and may require future work to
restore comparable styling.  But right now it also blocks compilation,
which means tests can't run at all.  Sacrifice minor styling for running
tests.

Remove outmoded comments.
Be verbose when copying configs.

Remove usused(?) trio of empty elements that now affects layout.

Replace tabs.

Abolish tabs.

Abolish tabs.

`index.html.erb` already includes a `col-md-9` and `div#content` before rendering
highlights or home, so they cannot declare addional columns or reuse
that identifier.

Chrome mode was last supported in IE 9, so it doesn't make sense with
IE=edge.

`IEMobile7` was obsolete five and a half years ago.  As the name
suggests it still contains rendering engine code from IE7.  Lulz.

Stop putting literal string separators in the breadcrumbs partial!
Just override the CSS content that sets the default separator.

Also use some `elsif` conditionals where the `on_x_page` checks are
exclusive.

No dots here.

Child of row must be a column (or clearfix, not clear!)

Main thing here is avoided error when `focus.offset()` is undefined.

- chevrons were renamed
- use hamburger instead of multiple modified bar icons
- separate styling

Hamburger now displays at the correct viewport (phone sized) but still
doesn't do anything.