Prep CRAN update

Signed-off-by: Peter Solymos <[email protected]>

R CMD testing on Linux

Signed-off-by: Peter Solymos <[email protected]>

Fix date issue and bump version to 0.1.5

Signed-off-by: Peter Solymos <[email protected]>

0.1.3 on CRAN

0.1.3 on CRAN