update DESCRIPTION (CRAN request)

DESCRIPTION

@@ -6,10 +6,10 @@ Authors@R: c(
         person("Thomas", "Nagler",, "[email protected]", role = c("aut", "cre")),
         person("Thibault", "Vatter",, "[email protected]", role = c("aut"))
         )
-Description: This package is an interface to 'vinecopulib', a
+Description: Provides an interface to 'vinecopulib', a
  high performance C++ library based on 'Boost', 'Eigen' and 'NLopt'. 
  It provides high-performance implementations of 
- the core features of the popular VineCopula package, in particular
+ the core features of the popular 'VineCopula' package, in particular
  inference algorithms for both vine copula and bivariate copula models.
  Advantages over VineCopula are a sleaker and more modern API, shorter runtimes, 
  especially in high dimensions, nonparametric and multi-parameter families.
@@ -21,7 +21,7 @@ Imports:
     graphics,
     grDevices,
     lattice,
-    Rcpp,
+    Rcpp (>= 0.12.12),
     stats,
     utils
 Suggests: