[goal] Migrate testing to ubuntu focal

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

Fixing:
Closes-Bug: #1886298
Bump the lower constraints for required deps which added python3.8
support in their later version.

This patch updates python version to py38 in package.json and
karma.conf.js as py36 is not avaialbale on focal. It also adds
libfontconfig1 in bindep.txt as phantomjs requires libfontconfg[2]

Story: #2007865
Task: #40188

Depends-On: https://review.opendev.org/#/c/749476/

[1] https://governance.openstack.org/tc/goals/selected/victoria/migrate-ci-cd-jobs-to-ubuntu-focal
[2] https://www.npmjs.com/package/phantomjs-prebuilt#linux-note

Change-Id: I01c88902bcb480bf3a11f377b2520596467294ed

bindep.txt

@@ -1,5 +1,6 @@
 # selenium tests
 firefox [selenium]
+libfontconfig1 [nodejs platform:dpkg]
 xvfb [selenium platform:dpkg]
 # already part of xorg-x11-server on openSUSE
 xorg-x11-server-Xvfb [selenium platform:redhat]

ironic_ui/karma.conf.js

@@ -17,7 +17,7 @@
 
   module.exports = function (config) {
     // This tox venv is setup in the post-install npm step
-    var toxPath = '../.tox/py36/lib/python3.6/site-packages/';
+    var toxPath = '../.tox/py38/lib/python3.8/site-packages/';
 
     config.set({
       preprocessors: {

lower-constraints.txt

@@ -2,7 +2,7 @@ alabaster==0.7.10
 appdirs==1.4.3
 asn1crypto==0.24.0
 certifi==2018.1.18
-cffi==1.11.5
+cffi==1.14
 chardet==3.0.4
 cliff==2.11.0
 cmd2==0.8.1

package.json

@@ -24,7 +24,7 @@
     "karma-threshold-reporter": "^0.1.15"
   },
   "scripts": {
-    "postinstall": "if [ ! -d .tox ] || [ ! -d .tox/py36 ]; then tox -epy36 --notest; fi",
+    "postinstall": "if [ ! -d .tox ] || [ ! -d .tox/py38 ]; then tox -epy38 --notest; fi",
     "test": "karma start ironic_ui/karma.conf.js --single-run",
     "lint": "eslint --no-color ironic_ui/static",
     "lintq": "eslint --quiet ironic_ui/static"