apptools, futures, numpy, scimath are core dependencies

[rahulporuri]

apptools is a core dependency on codetools but is not listed as one in the package __requires__. See https://github.com/enthought/codetools/blob/042e701cbd827916fd416ee351f7c6d3c2015910/codetools/contexts/data_context.py#L18 https://github.com/enthought/codetools/blob/042e701cbd827916fd416ee351f7c6d3c2015910/codetools/contexts/geo_context.py#L5 https://github.com/enthought/codetools/blob/042e701cbd827916fd416ee351f7c6d3c2015910/codetools/execution/async_executing_context.py#L13-L14 https://github.com/enthought/codetools/blob/042e701cbd827916fd416ee351f7c6d3c2015910/codetools/__init__.py#L9-L12

[itziakos]

I think that codetools is of a group of almost independent sub-packages so I would not think that dependencies in the context submodule are part of the core dependencies that should be part of the setup.py. I think that the dependencies of each sub-package should be captures in a extras