Upgrade requirements.txt

requirements.txt

 asn1crypto==0.24.0
 backports.ssl-match-hostname==3.5.0.1
 backports.weakref==1.0.post1
+bcrypt==3.1.4
 certifi==2018.4.16
 cffi==1.11.5
 chardet==3.0.4
 cryptography==2.3
-docker==3.5.1
+docker==3.6.0
 docker-pycreds==0.3.0
 idna==2.6
+paramiko==2.4.2
+pyasn1==0.4.2
 pycparser==2.18
+pynacl==1.1.2
 pyOpenSSL==18.0.0
 PyYAML==3.13
-requests==2.20.0
+requests==2.20.1
 six==1.11.0
 urllib3==1.22
-websocket-client==0.47.0
+websocket-client==0.48.0