add test for debian buster and fix linter

.gitlab-ci.yml

 linter:
-    image: debian:stretch
-    stage: test
-    script:
-    - apt update
-    - apt install -y python3
-    - python3 -V
-    - uname -a
-    - apt install -y sqlite3 locales-all git python3-flask python3-ldap3 python3-requests python3-lxml python3-icalendar python3-mysql.connector python3-requests python3-coverage pylint3
-    - pylint3 --indent-string='\t' --indent-after-paren=1 --output-format=text *.py | tee pylint.txt
-    artifacts:
-        paths:
-        - pylint.txt
+  image: debian:stretch
+  stage: test
+  script:
+  - apt update
+  - apt install -y python3
+  - python3 -V
+  - uname -a
+  - apt install -y sqlite3 locales-all git python3-flask python3-ldap3 python3-requests python3-lxml python3-icalendar python3-mysql.connector python3-requests python3-coverage pylint3
+  - pylint3 --indent-string='\t' --indent-after-paren=1 --max-line-length=140 --output-format=text *.py | tee pylint.txt
+  artifacts:
+      paths:
+      - pylint.txt
 
-unittest:
-    image: debian:stretch
-    stage: test
-    script:
-    - apt update
-    - apt install -y python3
-    - python3 -V
-    - uname -a
-    - apt install -y sqlite3 locales-all git python3-flask python3-ldap3 python3-requests python3-lxml python3-icalendar python3-mysql.connector python3-requests python3-coverage
-    - python3 -m coverage run runTests.py
-    - python3 -m coverage report --include "./*"
-    - python3 -m coverage report -m  --include "./*" > report.txt
-    - python3 -m coverage html --include "./*"
-    artifacts:
-        paths:
-        - htmlcov/*
-        - .coverage
-        - report.txt
+unittest: &unittest
+  image: debian:stretch
+  stage: test
+  script:
+  - apt update
+  - apt install -y python3
+  - python3 -V
+  - uname -a
+  - apt install -y sqlite3 locales-all git python3-flask python3-ldap3 python3-requests python3-lxml python3-icalendar python3-mysql.connector python3-requests python3-coverage
+  - python3 -m coverage run runTests.py
+  - python3 -m coverage report --include "./*"
+  - python3 -m coverage report -m  --include "./*" > report.txt
+  - python3 -m coverage html --include "./*"
+  artifacts:
+      paths:
+      - htmlcov/*
+      - .coverage
+      - report.txt
+
+unittest_buster:
+  <<: *unittest
+  image: debian:buster
 
 livetest:
-    image: debian:stretch
-    stage: test
-    script:
-    - apt update
-    - apt install -y python3
-    - python3 -V
-    - uname -a
-    - apt install -y python3-requests
+  image: debian:stretch
+  stage: test
+  script:
+  - apt update
+  - apt install -y python3
+  - python3 -V
+  - uname -a
+  - apt install -y python3-requests
 #    - ./tests/urlcheck_sinf.py
 
 deploy_staging:
-    image: archlinux/base
-    stage: deploy
-    script:
-    - pacman --noconfirm -Sy ansible git
-    
+  image: archlinux/base
+  stage: deploy
+  script:
+  - pacman --noconfirm -Sy ansible git
+