VIM 4.8.0

• fixed a bug in the distance computation when different variable types are used
• added imp_var and imp_suffix to irmi(), so it is more consistent with the other functions (#27)
• added parameter addRF, only RF to kNN(), to use random forest in combination with kNN()
• testthat package used for all tests
• added travis automatically building/checking
• covr for code coverage (vis functions are currently not covered by any tests)
• new imputation function matchImpute() for imputing randomly within groups