ENH: add type stubs from numpy-stubs

Add the type stubs and tests from numpy-stubs. Things this entails:

- Copy over the stubs (numpy/__init__.pyi and
  numpy/core/_internal.pyi)
  - The only modification made was removing `ndarray.tostring` since
    it is deprecated
- Update some setup.py files to include pyi files
- Move the tests from numpy-stubs/tests into numpy/tests
  - Skip them if mypy is not installed (planning on setting up CI in a
    future PR)
  - Add a mypy.ini; use it to configure mypy in the tests
    - It tells mypy where to find NumPy in the test env
    - It ignores internal NumPy type errors (since we only want to
      consider errors from the tests cases)
  - Some small edits were made to fix test cases that were emitting
    deprecation warnings
 - Add numpy/py.typed so that the types are picked up in an
   installed version of NumPy

1 files changed, 2 insertions, 0 deletions

diff --git a/numpy/setup.py b/numpy/setup.py
index 52db6a68b..c6498d101 100644
--- a/numpy/setup.py
+++ b/numpy/setup.py
@@ -18,6 +18,8 @@ def configuration(parent_package='',top_path=None):
     config.add_subpackage('random')
     config.add_subpackage('testing')
     config.add_data_dir('doc')
+    config.add_data_files('py.typed')
+    config.add_data_files('*.pyi')
     config.add_subpackage('tests')
     config.make_config_py() # installs __config__.py
     return config