r3.3.2用install_github('lchiffon/REmap')时，最后提示：
Error in loadNamespace(j <- i[[1L]], c(lib.loc, .libPaths()), versionCheck = vI[[j]]) :
  there is no package called 'Rcpp'
ERROR: lazy loading failed for package 'REmap'
* removing 'E:/Program Files/R-3.3.2/library/REmap'
Error: Command failed (1)
这怎么处理啊？