Use lib (not lib64) for libraries (#1024)

Previously some CMake files were getting installed with the `rmm` packages. These were installed because the library directory here did not line up with [the one used by `librmm`]( https://github.com/rapidsai/rmm/blob/97617ba826e89d69ff14457b1ede7d1478cbfa96/conda/recipes/librmm/build.sh#L3 ). This fixes that issue. Also should deduplicate any CMake files that are already included in `librmm` and drop them from `rmm`.

cc @robertmaynard @vyasr

Authors:
  - https://github.com/jakirkham

Approvers:
  - Robert Maynard (https://github.com/robertmaynard)
  - Vyas Ramasubramani (https://github.com/vyasr)
  - Ray Douglass (https://github.com/raydouglass)

URL: #1024

conda/recipes/rmm/build.sh

@@ -1,4 +1,4 @@
 # Copyright (c) 2018-2019, NVIDIA CORPORATION.
 
 # Script assumes the script is executed from the root of the repo directory
-./build.sh -v clean rmm
+./build.sh -v clean rmm --cmake-args=\"-DCMAKE_INSTALL_LIBDIR=lib\"