Revert "Revert the solr configuration"

This reverts commit ceeb8eae5de9e98984cd2c4699219a4ee96649d9.
Revert "Merge pull request #766 from okfn/766-stop-travis-build-when-deps-install-fails"

This reverts commit be38950f69517a5fd528a972f8ca6080a7ab5eef, reversing
changes made to cba4e6ccd350cde453efc5ca958c86b10c9a5d98.