random123: install uniform.hpp as well (#3856)

var/spack/repos/builtin/packages/random123/package.py

@@ -41,3 +41,5 @@ def install(self, spec, prefix):
         # We have to do our own install here.
         install_tree('include', prefix.include)
         install('./LICENSE', "%s" % prefix)
+        # used by some packages, e.g. quinoa
+        install('examples/uniform.hpp', prefix.include)