Introduce default assignment simplifications

There are many simplifications in pystencils that are usually not applied. They can be applied now by using a simple argument in the configuration.

Fixes #39 (closed)

.gitlab-ci.yml

@@ -238,6 +238,7 @@ pycodegen-integration:
   when: manual
   allow_failure: true
   script:
+    - conda init bash
     - conda activate pystencils_dev
     - git clone https://gitlab-ci-token:${CI_JOB_TOKEN}@i10git.cs.fau.de/pycodegen/pycodegen.git
     - cd pycodegen