Provide a fallback default version when the network is unavailable

[jcoyne]

No description provided.

[cbeer]

If the network isn't available, presumably you won't be able to download that version either? Maybe we need some logic to look at locally cached versions and pick the latest?

[jcoyne]

@cbeer yeah, I hit this on an airplane. I didn't have the network up, but I had a cached version available.

[jcoyne]

Here's another case where it's not allowing connections from travis:

Caused by:

Errno::ECONNREFUSED: Failed to open TCP connection to svn.apache.org:443 (Connection refused - connect(2) for "svn.apache.org" port 443)

/home/travis/build/samvera/hyrax/vendor/bundle/ruby/2.4.0/gems/faraday-0.12.2/lib/faraday/adapter/net_http.rb:78:in `perform_request'

/home/travis/build/samvera/hyrax/vendor/bundle/ruby/2.4.0/gems/faraday-0.12.2/lib/faraday/adapter/net_http.rb:38:in `block in call'

/home/travis/build/samvera/hyrax/vendor/bundle/ruby/2.4.0/gems/faraday-0.12.2/lib/faraday/adapter/net_http.rb:85:in `with_net_http_connection'

/home/travis/build/samvera/hyrax/vendor/bundle/ruby/2.4.0/gems/faraday-0.12.2/lib/faraday/adapter/net_http.rb:33:in `call'

/home/travis/build/samvera/hyrax/vendor/bundle/ruby/2.4.0/gems/faraday-0.12.2/lib/faraday/request/url_encoded.rb:15:in `call'

/home/travis/build/samvera/hyrax/vendor/bundle/ruby/2.4.0/gems/faraday-0.12.2/lib/faraday/rack_builder.rb:141:in `build_response'

/home/travis/build/samvera/hyrax/vendor/bundle/ruby/2.4.0/gems/faraday-0.12.2/lib/faraday/connection.rb:386:in `run_request'

/home/travis/build/samvera/hyrax/vendor/bundle/ruby/2.4.0/gems/faraday-0.12.2/lib/faraday/connection.rb:149:in `get'

/home/travis/build/samvera/hyrax/vendor/bundle/ruby/2.4.0/gems/faraday-0.12.2/lib/faraday.rb:100:in `method_missing'

/home/travis/build/samvera/hyrax/vendor/bundle/ruby/2.4.0/gems/solr_wrapper-1.1.0/lib/solr_wrapper/configuration.rb:159:in `fetch_latest_version'

presumably this is due to throttling?