pin major version of dependencies

setup.py

@@ -23,7 +23,7 @@
     packages=["pytest_pylint"],
     entry_points={"pytest11": ["pylint = pytest_pylint.plugin"]},
     python_requires=">=3.7",
-    install_requires=["pytest>=5.4", "pylint>=2.3.0", "toml>=0.7.1"],
+    install_requires=["pytest~=5.4", "pylint~=2.3", "toml~=0.7"],
     setup_requires=["pytest-runner"],
     tests_require=["coverage", "flake8", "black", "isort"],
     classifiers=[