Get rid of cwd modifications in tests

conftest.py

@@ -9,6 +9,7 @@ import pytest
 import jedi
 from jedi.api.environment import get_system_environment, InterpreterEnvironment
 from jedi._compatibility import py_version
+from test.helpers import test_dir
 
 collect_ignore = [
     'setup.py',
@@ -109,6 +110,12 @@ def Script(environment):
     return partial(jedi.Script, environment=environment)
 
 
+@pytest.fixture(scope='session')
+def ScriptWithProject(Script):
+    project = jedi.Project(test_dir)
+    return partial(jedi.Script, project=project)
+
+
 @pytest.fixture(scope='session')
 def get_names(Script):
     return lambda code, **kwargs: Script(code).get_names(**kwargs)