Fixed the ukrdc rake task when supporting exporting specific patients
Fixed the ukrdc rake task when supporting exporting specific patients

Support for specific patient ids was broken.
Once can run `bundle exec rake -D` to see example usage.
For example to get patientids 1 and 2 and changes since 23-Feb-2018
`bundle exec rake ukrdc:export["2018-02-23","1 2”]`

airslie/renalware-core,airslie/renalware-core,airslie/renalware-core,airslie/renalware-core