Change logic for detecting categorical variables

Basically the client now has to send this information.
Merge branch 'master' into features/boxplot_multivar
Tests: stubbing of core-db services into sep class
Remove redundant argument
Add another helper to ConfiguratorTestsHelper

List<ClinicalVariableColumn>
    createClinicalVariableColumns(List<String> conceptPaths,
                                  boolean needsLabel = false)
BoxPlot: add support for mult numeric clin vars
To add flags for both dependent and independent variables whether they are categorical or non-categorical.
Merge pull request #13 from thehyve/features/boxplot_multivar

Features/boxplot multivar