Fix l-c testing for ubuntu focal

As per victoria cycle testing runtime and community goal[1]
we need to migrate upstream CI/CD to Ubuntu Focal(20.04).

- Bump the lower constraints for required deps which added python3.8 support
in their later version.

Story: #2007865
Task: #40206

[1] https://governance.openstack.org/tc/goals/selected/victoria/migrate-ci-cd-jobs-to-ubuntu-focal.html

Change-Id: I1888e2c4e7bdcad425e8b49c8a03fa8b2f9fba7d

lower-constraints.txt

@@ -7,7 +7,7 @@ Babel==2.5.3
 bcrypt==3.1.4
 botocore==1.5.1
 certifi==2018.1.18
-cffi==1.11.5
+cffi==1.14.0
 chardet==3.0.4
 cliff==2.11.0
 cmd2==0.8.1
@@ -27,7 +27,7 @@ extras==1.0.0
 fasteners==0.14.1
 fixtures==3.0.0
 future==0.16.0
-greenlet==0.4.13
+greenlet==0.4.15
 idna==2.6
 imagesize==1.0.0
 iso8601==0.1.12
@@ -61,7 +61,7 @@ oslo.serialization==2.25.0
 oslo.service==1.24.0
 oslo.utils==3.33.0
 packaging==17.1
-paramiko==2.0.0
+paramiko==2.7.1
 Paste==2.0.3
 PasteDeploy==1.5.2
 pbr==2.0.0
@@ -90,7 +90,7 @@ python-openstackclient==3.12.0
 python-subunit==1.2.0
 python-swiftclient==3.2.0
 pytz==2018.3
-PyYAML==3.12
+PyYAML==3.13
 repoze.lru==0.7
 requests==2.18.4
 requestsexceptions==1.4.0

requirements.txt

@@ -22,7 +22,7 @@ oslo.service!=1.28.1,>=1.24.0 # Apache-2.0
 cryptography>=2.1 # Apache-2.0
 PyMySQL>=0.7.6 # MIT License
 pymongo!=3.1,>=3.0.2 # Apache-2.0
-paramiko>=2.0.0 # LGPLv2.1+
+paramiko>=2.7.1 # LGPLv2.1+
 
 apscheduler>=3.0.5 # MIT License
 psutil>=3.2.2 # BSD