Update requirements to fix CVE (#22)

Author: Tao Feng

requirements.txt

@@ -46,7 +46,7 @@ py==1.5.3
 pyhocon==0.3.42
 pyparsing==2.2.0
 six==1.11.0
-sqlalchemy==1.2.7
+sqlalchemy==1.3.0
 wheel==0.31.1
 neo4j-driver==1.6.0
 neotime==1.0.0