Get Rid of nobuild, nolink, and alldeps (#2765)

* Removing the nobuild, nolink, and alldeps dependency types in favor of being explicit.
* This will help with maintenance going forward, as adding more dependency types won't affect existing declared dependencies in weird ways.
* default deptype is still `('build', 'link')`

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

@@ -44,7 +44,7 @@ class PyScipy(Package):
     depends_on('py-nose', type='build')
     # Known not to work with 2.23, 2.25
     depends_on('binutils@2.26:', type='build')
-    depends_on('py-numpy@1.7.1:+blas+lapack', type=nolink)
+    depends_on('py-numpy@1.7.1:+blas+lapack', type=('build', 'run'))
     depends_on('blas')
     depends_on('lapack')