Add py-setuptools as dependency

With the addition of dependency types and with `py-setuptools` set as
type='build' there are more packages that need to have `py-setuptools`
added as a dependency.

This PR adds that dependency for the following packages:
- py-h5py
- py-networkx
- py-pytables
- py-scikit-image

var/spack/repos/builtin/packages/py-h5py/package.py

@@ -43,6 +43,7 @@ class PyH5py(Package):
     # Build dependencies
     depends_on('py-cython@0.19:', type='build')
     depends_on('pkg-config', type='build')
+    depends_on('py-setuptools', type='build')
     depends_on('hdf5@1.8.4:')
     depends_on('hdf5+mpi', when='+mpi')
     depends_on('mpi', when='+mpi')

var/spack/repos/builtin/packages/py-networkx/package.py

@@ -34,6 +34,7 @@ class PyNetworkx(Package):
     extends('python')
 
     depends_on('py-decorator', type=nolink)
+    depends_on('py-setuptools', type='build')
 
     def install(self, spec, prefix):
         python('setup.py', 'install', '--prefix=%s' % prefix)

var/spack/repos/builtin/packages/py-pytables/package.py

@@ -37,6 +37,7 @@ class PyPytables(Package):
     depends_on('py-numpy', type=nolink)
     depends_on('py-numexpr', type=nolink)
     depends_on('py-cython', type=nolink)
+    depends_on('py-setuptools', type='build')
 
     def install(self, spec, prefix):
         env["HDF5_DIR"] = spec['hdf5'].prefix

var/spack/repos/builtin/packages/py-scikit-image/package.py

@@ -42,6 +42,7 @@ class PyScikitImage(Package):
     depends_on('py-six', type=nolink)
     depends_on('py-scipy', type=nolink)
     depends_on('py-matplotlib', type=nolink)
+    depends_on('py-setuptools', type='build')
 
     def install(self, spec, prefix):
         python('setup.py', 'install', '--prefix=%s' % prefix)