Modernize OSX wheel names.

- Update multibuild to 7287f69
- Update config.sh for 64 bit only.

Author: charris

config.sh

@@ -15,7 +15,14 @@ function build_wheel {
 
 function build_libs {
     local plat=${1:-$PLAT}
-    local tar_path=$(abspath $(get_gf_lib "openblas-${OPENBLAS_VERSION}" "$plat"))
+    # Force 64-bit OpenBLAS library for macOS intel (dual arch)
+    # builds. For these builds, we pretend to be dual arch, but in
+    # fact we're only using the 64-bit build of OpenBLAS
+    if [ -n $IS_OSX ] && [ $plat == intel ]; then
+        plat=x86_64
+    fi
+    local tar_fname=$(get_gf_lib "openblas-${OPENBLAS_VERSION}" "$plat")
+    local tar_path=$(abspath $tar_fname)
     # Sudo needed for macOS
     local use_sudo=""
     [ -n "$IS_OSX" ] && use_sudo="sudo"