tapkee 1.2:
 examples improved;
 suggested packages are now used conditionally (rgl does not work on new macOS processors).

tapkee 1.1:
 'tapkee_methods' vignette added;
 improvements in examples;
 Tapkee() checks also for the empty input file;
 new 'package?tapkee' help file with installation instructions

tapkee 1.0:
 first release

