Fix py-scientificpython and py-argcomplete dependencies (#2420)

* add missing py-numpy dependency to scipy

* add missing setuptools build dependency to py-argcomplete

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

@@ -33,6 +33,7 @@ class PyArgcomplete(Package):
 
     version('1.1.1', '89a3839096c9f991ad33828e72d21abf')
 
+    depends_on('py-setuptools', type='build')
     extends('python')
 
     def install(self, spec, prefix):

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

@@ -35,6 +35,8 @@ class PyScientificpython(Package):
     url      = "https://sourcesup.renater.fr/frs/download.php/file/4411/ScientificPython-2.8.1.tar.gz"
     version('2.8.1', '73ee0df19c7b58cdf2954261f0763c77')
 
+    depends_on('py-numpy')
+
     extends('python')
 
     def install(self, spec, prefix):