feat(cli): add support for execution via 'python -m' (#395)

Co-authored-by: Saurabh Kumar <theskumar@noreply.users.github.com>

setup.py

@@ -37,7 +37,7 @@ def read_files(files):
     },
     entry_points={
         "console_scripts": [
-            "dotenv=dotenv.cli:cli",
+            "dotenv=dotenv.__main__:cli",
         ],
     },
     license='BSD-3-Clause',

src/dotenv/__main__.py

@@ -0,0 +1,6 @@
+"""Entry point for cli, enables execution with `python -m dotenv`"""
+
+from .cli import cli
+
+if __name__ == "__main__":
+    cli()

src/dotenv/cli.py

@@ -158,7 +158,3 @@ def run_command(command: List[str], env: Dict[str, str]) -> int:
     _, _ = p.communicate()
 
     return p.returncode
-
-
-if __name__ == "__main__":
-    cli()