Added CI

.gitlab-ci.yml

+stages:
+  - test
+  - lint
+  - coverage
+
+variables:
+  PYLINT_CMD: >
+    (pylint grext --exit-zero > pylint.out) || true
+  PIP_CACHE_DIR: "$CI_PROJECT_DIR/.cache/pip"
+
+default:
+  image: python:latest
+  cache:
+    paths:
+      - .cache/pip
+  before_script:
+    - python -V
+    - pip install virtualenv
+    - virtualenv venv
+    - source venv/bin/activate
+    - pip install .
+    - pip install pylint anybadge coverage
+  tags:
+    - Maths
+
+test:
+  stage: test
+  script:
+    - coverage run -m pytest
+  artifacts:
+    paths:
+      - .coverage
+
+lint:
+  stage: lint
+  script:
+    - mkdir -p ./public
+    - pylint grext --exit-zero | tee pylint.out
+    - score=$(sed -n 's/^Your code has been rated at \([-0-9.]*\)\/.*/\1/p' pylint.out)
+    - echo "Pylint score was $score"
+    - anybadge --value=$score --file=public/pylint_badge.svg pylint
+    - echo $score | awk '{if( $1 > 8.0 ) exit 0; exit 1;}'
+  artifacts:
+    paths:
+      - public/pylint_badge.svg
+
+coverage:
+  stage: coverage
+  script:
+    - mkdir -p ./public
+    - coverage report | tee report.out
+    - covperc=`cat report.out | grep 'TOTAL' | sed -e 's/%//g' | awk '{print $4}'`
+    - anybadge --value=$covperc --file=public/coverage.svg coverage
+  artifacts:
+    paths:
+      - public/coverage.svg