Bump pytest to 4.x series

Signed-off-by: Jason T. Brown <[email protected]>

Author: vpipkt

pyrasterframes/src/main/python/setup.py

@@ -170,7 +170,7 @@ def dest_file(self, src_file):
         'folium',
     ],
     tests_require=[
-        'pytest==3.4.2',
+        'pytest>=4.0.0,<5.0.0',
         'pypandoc',
         'numpy>=1.7',
         'Shapely>=1.6.0',