Update pylint from 2.4.4 to 2.5.0 (#150)

Author: pyup-bot

requirements-tests.txt

@@ -2,6 +2,6 @@
 coveralls==2.0.0
 coverage==5.1
 nose==1.3.7
-pylint==2.4.4
+pylint==2.5.0
 tox==3.14.6
 safety==1.9.0