conftest: Use fast hypothesis profile if none has been explicitely set

This will prevent bad surprises when users simply invoke pytest in the root folder
of swh-web as default profile makes tests execution slow and tests can fail depending
on the hypothesis version used.

swh/web/tests/conftest.py

@@ -45,6 +45,10 @@ settings.register_profile(
 
 
 def pytest_configure(config):
+    # Use fast hypothesis profile by default if none has been
+    # explicitly specified in pytest option
+    if config.getoption('--hypothesis-profile') is None:
+        settings.load_profile('swh-web-fast')
     # Small hack in order to be able to run the unit tests
     # without static assets generated by webpack.
     # Those assets are not really needed for the Python tests