CI: enable pypy3, remove NumPyPy

Author: mgeier

.travis.yml

@@ -9,14 +9,10 @@ python:
   - "3.9"
   - "nightly"
   - "pypy"
-  # TODO: Enable pypy3 once NumPy is working there, see	
-  # https://bitbucket.org/pypy/pypy/issues/1567/	
-  #- "pypy3"
+  - "pypy3"
 addons:
   apt:
     packages:
     - libsndfile1
-install:
-  - "if [[ $TRAVIS_PYTHON_VERSION == pypy ]]; then pip install git+https://bitbucket.org/pypy/numpy.git ; fi"
 script:
   - python setup.py test