Fix workflow run

Author: Sparks29032

.coveragerc

@@ -1,6 +1,6 @@
 [run]
 source = 
-    diffpy/pdfmorph/
+    src/diffpy/pdfmorph/
 [report]
 omit =
     */python?.?/*

.github/workflows/main.yml

@@ -50,6 +50,6 @@ jobs:
         shell: bash -l {0}
         run: |
           conda activate test
-          coverage run run_tests.py
+          python -m coverage run run_tests.py  # use `python -m` to search for modules within env
           coverage report -m
           codecov

pyproject.toml

@@ -35,6 +35,9 @@ classifiers = [
 Homepage = "https://github.com/diffpy/diffpy.pdfmorph/"
 Issues = "https://github.com/diffpy/diffpy.pdfmorph/issues"
 
+[tool.pytest.ini_options]
+pythonpath = ["src"]
+
 [tool.setuptools-git-versioning]
 enabled = true
 template = "{tag}"