simplify sphinx prepping in gitlab-ci

.gitlab-ci.yml

@@ -2,6 +2,8 @@
 image: python:3.8-slim
 .pip_install_default: &pip_install_default
     - pip install scipy matplotlib h5py webdavclient3
+.pip_install_sphinx: &pip_install_sphinx
+    - pip install sphinx sphinxcontrib-confluencebuilder sphinxcontrib-blockdiag blockdiag sphinxcontrib-restbuilder sphinx_rtd_theme numpy m2r2
 variables:
   TWINE_REPOSITORY_URL: https://artifactory.esss.lu.se/artifactory/api/pypi/ics-pypi
 
@@ -27,7 +29,7 @@ pages:
   script:
     - apt update
     - apt install git -y
-    - pip install sphinx sphinxcontrib-blockdiag blockdiag sphinxcontrib-restbuilder sphinx_rtd_theme numpy m2r2
+    - *pip_install_sphinx
     - python setup.py install
     - sphinx-build -b html -d public/doctrees   doc public
   artifacts:
@@ -41,7 +43,7 @@ confluence-doc:
   script:
     - apt update
     - apt install git -y
-    - pip install sphinx sphinxcontrib-confluencebuilder sphinxcontrib-blockdiag blockdiag sphinxcontrib-restbuilder sphinx_rtd_theme numpy m2r2
+    - *pip_install_sphinx
     - python setup.py install
     - sphinx-build -M confluence "doc" "doc"
   only: