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-iminuit/package.py

@@ -38,8 +38,8 @@ class PyIminuit(Package):
     depends_on('py-setuptools', type='build')
 
     # Optional dependencies
-    depends_on('py-numpy', type=nolink)
-    depends_on('py-matplotlib', type=nolink)
+    depends_on('py-numpy', type=('build', 'run'))
+    depends_on('py-matplotlib', type=('build', 'run'))
     depends_on('py-cython', type='build')
 
     def install(self, spec, prefix):