Switch CI to use poetry

.gitlab-ci.yml

@@ -6,12 +6,12 @@ stages:
   - deploy
 
 # Re-usable block to install (and cache) Poetry and openflexure-microscope-server
-.poetry-install-template: &poetry-install
+.python-install-template: &python-install
   before_script:
-    - curl -sSL https://raw.githubusercontent.com/python-poetry/poetry/master/get-poetry.py | python
-    - source $HOME/.poetry/env
-    - poetry config virtualenvs.in-project true
-    - poetry install -vv
+    - python3 -m venv .venv        # NB this does not overwrite an existing cached venv
+    - source .venv/bin/activate 
+    - pip install pipenv           # Should be cached after first run
+    - pipenv install               # Should be cached after first run - will just check packages are present
   cache:
     key: "${CI_COMMIT_REF_SLUG}"
     paths:
@@ -34,7 +34,7 @@ pylint:
   image: python:3.7
   retry: 1
 
-  <<: *poetry-install
+  <<: *python-install
 
   script:
     - poetry run poe pylint
@@ -51,7 +51,7 @@ mypy:
   image: python:3.7
   retry: 1
 
-  <<: *poetry-install
+  <<: *python-install
 
   script:
     - poetry run poe mypy
@@ -73,7 +73,7 @@ black:
   retry: 1
   allow_failure: true
 
-  <<: *poetry-install
+  <<: *python-install
 
   script:
     # Run static build script
@@ -91,7 +91,7 @@ pytest:
   image: python:3.7
   retry: 1
 
-  <<: *poetry-install
+  <<: *python-install
 
   script:
     - poetry run poe test