chore: pin dependencies (microsoft#216)

Author: mxschmitt

setup.py

@@ -27,7 +27,7 @@
     url="https://github.com/Microsoft/playwright-python",
     packages=["playwright"],
     include_package_data=True,
-    install_requires=["greenlet", "pyee", "typing-extensions"],
+    install_requires=["greenlet==0.4.17", "pyee==8.0.1", "typing-extensions"],
     classifiers=[
         "Topic :: Software Development :: Testing",
         "Topic :: Internet :: WWW/HTTP :: Browsers",