Fix running pytest with coverage

Pytest and coverage would get confused for an unknown reason presumably
related to installed packages vs. packages in the current directory. Not
installing bloscpack and running pytest with PYTHONPATH=. fixes this
issue.

.github/workflows/testbloscpack.yml

@@ -21,8 +21,6 @@ jobs:
       run: |
         pip install -r requirements.txt
         pip install -r test_requirements.txt
-    - name: Install from source
-      run: pip install .
     - name: Run tests
       run: ./test.sh
     - name: Report coverage

test.sh

@@ -7,7 +7,7 @@ echo "Testing command line interface with cram"
 COVERAGE=1 cram --verbose $@  test_cmdline/*.cram
 cram_exit=$?
 echo "Executing unit tests with pytest"
-pytest --cov=bloscpack test
+PYTHONPATH=. pytest --cov=bloscpack test
 pytest_exit=$?
 if [ $cram_exit -gt 0 ] || [ $pytest_exit -gt 0 ] ; then
     echo "some tests failed"