fix Makefile for rpkg

Makefile

@@ -580,19 +580,19 @@ rpkg:
 	cp -rf lib/libmxnet.so R-package/inst/libs
 	mkdir -p R-package/inst/include
 	cp -rf include/* R-package/inst/include
+	rm R-package/inst/include/dmlc
+	rm R-package/inst/include/nnvm
 	cp -rf 3rdparty/dmlc-core/include/* R-package/inst/include/
 	cp -rf 3rdparty/tvm/nnvm/include/* R-package/inst/include
 	Rscript -e "if(!require(devtools)){install.packages('devtools', repo = 'https://cloud.r-project.org/')}"
+	Rscript -e "if(!require(devtools)||packageVersion('roxygen2') < '6.1.1'){install.packages('roxygen2', repo = 'https://cloud.r-project.org/')}"
 	Rscript -e "library(devtools); library(methods); options(repos=c(CRAN='https://cloud.r-project.org/')); install_deps(pkg='R-package', dependencies = TRUE)"
 	cp R-package/dummy.NAMESPACE R-package/NAMESPACE
 	echo "import(Rcpp)" >> R-package/NAMESPACE
 	R CMD INSTALL R-package
-	Rscript -e "if (!require('roxygen2')||packageVersion('roxygen2') < '5.0.1'){\
-	    devtools::install_version('roxygen2',version='5.0.1',\
-	    repos='https://cloud.r-project.org/',quiet=TRUE)}"
 	Rscript -e "require(mxnet); mxnet:::mxnet.export('R-package'); warnings()"
 	rm R-package/NAMESPACE
-	Rscript -e "require(roxygen2); roxygen2::roxygenise('R-package'); warnings()"
+	Rscript -e "devtools::document('R-package'); warnings()"
 	R CMD INSTALL R-package
 
 rpkgtest:

R-package/DESCRIPTION

@@ -29,7 +29,7 @@ Suggests:
     imager,
     covr
 Depends:
-    R (>= 3.3.0)
+    R (>= 3.4.4)
 LinkingTo: Rcpp
 VignetteBuilder: knitr
-RoxygenNote: 6.1.0
+RoxygenNote: 6.1.1