remove coreutils deps

- loading this as a runtime dep causes problems on cross-compiled environments
- maybe find a workaround if it turns out we really need this somewhere?

packages/margo/package.py

@@ -37,6 +37,4 @@ class Margo(AutotoolsPackage):
     depends_on('autoconf@2.65:', type=("build"))
     depends_on('automake', type=("build"))
     depends_on('libtool', type=("build"))
-    # 'timeout' is part of coreutils
-    depends_on('coreutils')
     depends_on('pkg-config', type=("build"))

packages/pmem/package.py

@@ -38,7 +38,6 @@ class Pmem(Package):
 
     # experimental rpmem
     depends_on('libfabric@1.4.2:')
-    depends_on('coreutils@8.15:')
 
     # documentation requires doxygen and a bunch of other depenedncies that
     # were not working properly on our contianers