make tests directory a proper python module

tests/conftest.py

@@ -1,4 +1,4 @@
 pytest_plugins = [
-    "direnv_project",
-    "root",
+    "tests.direnv_project",
+    "tests.root",
 ]

tests/direnv_project.py

@@ -6,7 +6,8 @@ from tempfile import TemporaryDirectory
 from typing import Iterator
 
 import pytest
-from procs import run
+
+from .procs import run
 
 
 @dataclass

tests/test_gc.py

@@ -3,9 +3,9 @@ import sys
 import unittest
 
 import pytest
-from direnv_project import DirenvProject
-from procs import run
 
+from .direnv_project import DirenvProject
+from .procs import run
 
 def common_test(direnv_project: DirenvProject) -> None:
     run(["nix-collect-garbage"])

tests/test_use_nix.py

@@ -5,8 +5,9 @@ import unittest
 from typing import Optional
 
 import pytest
-from direnv_project import DirenvProject
-from procs import run
+
+from .direnv_project import DirenvProject
+from .procs import run
 
 
 def direnv_exec(