test kwant against latest qsymm

This is a decent integration test.
Closes #9.

.gitlab-ci.yml

 variables:
   GIT_SUBMODULE_STRATEGY: recursive
+  KWANT_QSYMM_TEST_PATH_SCRIPT: >
+    import os;
+    import kwant.tests.test_qsymm;
+    print(os.path.abspath(kwant.tests.test_qsymm.__file__));
 
 image: quantumtinkerer/research
 
@@ -19,3 +23,15 @@ test latest requirements:
     - source activate qsymm-latest
     - py.test qsymm/ --cov=qsymm --verbose --cov-report term
   stage: test
+
+test kwant against latest qsymm:
+  script:
+    - conda env create -f environment-latest.yml
+    - source activate qsymm-latest
+    # Get bleeding-edge Kwant
+    - conda install cython
+    - pip install .  # need to install qsymm so that the kwant test can find it
+    - pip install git+https://gitlab.kwant-project.org/kwant/kwant.git
+    - export KWANT_QSYMM_PATH=$(python -c "$KWANT_QSYMM_TEST_PATH_SCRIPT")
+    - py.test $KWANT_QSYMM_PATH
+  stage: test