Fix np.issubdtype warning

[marioyc]

Modify check of subtypes of np.int for subtypes of np.signedinteger or np.unsignedinteger

Fixes #2188

[menshikh-iv]

Hi @marioyc, thanks for PR, can you please

1. Fix this issue everywhere (not only in matutils.py):

ivan@P50:~/release/gensim$ find gensim -name "*.py" | xargs grep "np.issubdtype"
gensim/test/test_ldamodel.py:                self.assertTrue(np.issubdtype(v, float))
gensim/test/test_ldamodel.py:            self.assertTrue(np.issubdtype(v, float))
gensim/test/test_ldamodel.py:                self.assertTrue(np.issubdtype(v, float))
gensim/test/test_ldamodel.py:                self.assertTrue(np.issubdtype(v, float))
gensim/test/test_ldamodel.py:                self.assertTrue(np.issubdtype(v, float))
gensim/test/test_ldamodel.py:            self.assertTrue(np.issubdtype(v, float))
gensim/test/test_ldamodel.py:            self.assertTrue(np.issubdtype(probability, float))
gensim/test/test_ldamodel.py:            self.assertTrue(np.issubdtype(probability, float))
gensim/test/test_matutils.py:        self.assertTrue(np.issubdtype(unit_vector.dtype, float))
gensim/test/test_matutils.py:        self.assertTrue(np.issubdtype(unit_vector.dtype, float))
gensim/test/test_matutils.py:        self.assertTrue(np.issubdtype(unit_vector.dtype, float))
gensim/test/test_matutils.py:        self.assertTrue(np.issubdtype(unit_vector.dtype, float))
gensim/test/test_matutils.py:        self.assertTrue(np.issubdtype(unit_vector.dtype, float))
gensim/test/test_matutils.py:        self.assertTrue(np.issubdtype(unit_vector.dtype, float))
gensim/matutils.py:            if np.issubdtype(vec.dtype, np.int):
gensim/matutils.py:            if np.issubdtype(vec.dtype, np.int):

2. Put here any link for confrimation than proposed way are correct (maybe some info from numpy doc or something similar)

[marioyc]

Hi @menshikh-iv ,

from the numpy docs (https://docs.scipy.org/doc/numpy/reference/arrays.scalars.html) it looks like the correct types on hierarchy are np.integer and np.floating

[menshikh-iv]

Thank you @marioyc, congratz with the first contribution, happy hacktoberfest 🌟