TST: Add entry-point invocation to tox.ini

tox.ini

@@ -9,6 +9,7 @@ deps = .
     # TODO: Make this f-branch sensitive
     git+https://gitlab.indiscale.com/caosdb/src/caosdb-pylib.git@dev
     git+https://gitlab.indiscale.com/caosdb/src/caosdb-advanced-user-tools.git@dev
-commands=py.test --cov=caosdb -vv {posargs}
+commands= caosdb-crawler --help
+    py.test --cov=caosdb -vv {posargs}
 [flake8]
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