faster build on travis

Author: rusty1s

.travis.yml

@@ -113,7 +113,7 @@ install:
   - pip install flake8
   - pip install codecov
   - pip install scipy==1.4.1
-  - pip install .[test]
+  - pip install -e .
 script:
   - flake8 .
   - python setup.py test

setup.py

@@ -101,7 +101,8 @@ def get_extensions():
     extras_require={'test': tests_require},
     ext_modules=get_extensions() if not BUILD_DOCS else [],
     cmdclass={
-        'build_ext': BuildExtension.with_options(no_python_abi_suffix=True)
+        'build_ext':
+        BuildExtension.with_options(no_python_abi_suffix=True, use_ninja=False)
     },
     packages=find_packages(),
 )