PyPy3 support (#2146)

* Error out eval_file

* Enable dynamic attribute support for Pypy >= 6

* Add a test for dynamic attribute support

* Skip test for eval_file on pypy

* Workaround for __qualname__ on PyPy3

* Add a PyPy3.6 7.3.0 build

* Only disable in PyPy3

* Fix travis testing

* No numpy and scipy for pypy

* Enable test on pypy2

* Fix logic in eval_file

* Skip a few tests due to bugs in PyPy

* scipy wheels are broken. make pypy2 a failrue

Co-authored-by: Andreas Kloeckner <inform@tiker.net>
diff --git a/tests/test_local_bindings.py b/tests/test_local_bindings.py
index b380376..be841a7 100644
--- a/tests/test_local_bindings.py
+++ b/tests/test_local_bindings.py
@@ -152,6 +152,7 @@
     assert m.local_cpp_types_addr() != cm.local_cpp_types_addr()
 
 
+@pytest.bug_in_pypy
 def test_stl_caster_vs_stl_bind(msg):
     """One module uses a generic vector caster from `<pybind11/stl.h>` while the other
     exports `std::vector<int>` via `py:bind_vector` and `py::module_local`"""