updated gitlab-ci to install requirements before building the documentation....

I believe the problem with autodoc constructing the documentation was caused by missing dependencies. This merge request install all pyicon dependencies before attempting to build the documentation.

.gitlab-ci.yml

 pages:
   script:
+  - apk update
+  - apk upgrade
+  - apk add make
   - conda env create -f ci/requirements_py311.yml
   - source activate pyicon_py311
   - pip install -e .