bump multiple dependency versions from snyk

requirements.txt

@@ -4,27 +4,27 @@ autobahn==18.3.1
 Automat==0.6.0
 baseplate==0.30.6
 blinker==1.3
-certifi==2018.11.29
+certifi==2019.9.11
 cffi==1.11.5
 chardet==3.0.4
 Cheetah==2.4.4
 Click==7.0
 colorama==0.2.5
 configobj==4.7.2
 constantly==15.1.0
-cryptography==2.2.2
+cryptography==2.3
 enum34==1.1.6
 Flask==1.0.2
 Flask-Mail==0.9.1
 Flask-SQLAlchemy==2.3.2
-gunicorn==19.8.1
-html5lib==0.999
+gunicorn==19.10.0
+html5lib==1.0.1
 hyperlink==18.0.0
 idna==2.6
 incremental==17.5.0
 ipaddress==1.0.19
 itsdangerous==1.1.0
-Jinja2==2.10
+Jinja2==2.10.1
 jsonpatch==1.3
 jsonpointer==1.0
 Markdown==2.6.11
@@ -43,14 +43,14 @@ PyJWT==1.7.1
 pyOpenSSL==17.5.0
 pyserial==2.6
 pytz>=2018.9
-PyYAML==4.2b2
-requests==2.20.1
+PyYAML==5.3.1
+requests==2.23.0
 service-identity==17.0.0
 six==1.11.0
 SQLAlchemy==1.3.0
 thrift==0.13.0
 Twisted==16.1.0
 txaio==2.9.0
-urllib3==1.24.2
+urllib3==1.25.8
 Werkzeug==0.14.1
 zope.interface==4.4.3