CIMI: fix test failure due to sequel/sqlite error type change

Travis is failing with:
https://travis-ci.org/deltacloud/deltacloud-core/jobs/8763200

[Sequel::InvalidValue] exception expected, not
  Class: <Sequel::NotNullConstraintViolation>
  Message: <"SQLite3::ConstraintException: providers.driver may not be NULL">
  ---Backtrace---
  /home/travis/.rvm/gems/ruby-1.9.3-p448/gems/sqlite3-1.3.7/lib/sqlite3/statement.rb:108:in `step'
...
  /home/travis/.rvm/gems/ruby-1.9.3-p448/gems/sequel-4.0.0/lib/sequel/adapters/sqlite.rb:181:in `block (2 levels) in _execute'

Seems to happen because sqlite changed its error message and sequel changed the wrapping error.
See:
https://github.com/jeremyevans/sequel/commit/3b74892e922306539fe29a37aaf895b9e102f402#L12R319

and old sqlite error message:

  [Sequel::NotNullConstraintViolation] exception expected, not
  Class: <Sequel::InvalidValue>
  Message: <"nil/NULL is not allowed for the driver column">
  ---Backtrace---
  /root/.rbenv/versions/1.9.3-p448/lib/ruby/gems/1.9.1/gems/sequel-3.48.0/lib/sequel/model/base.rb:1986:in `typecast_value'