Update scrypt from 0.8.6 to 0.8.7

requirements-test.txt

@@ -7,7 +7,7 @@ requests==2.21.0
 websocket-client==0.54.0
 pytz==2018.9
 pycryptodomex==3.7.3
-scrypt==0.8.6
+scrypt==0.8.7
 Events==0.3
 cryptography==2.5
 pyyaml>=4.2b1