0.4 version for pypi release (#47)

Summary:
This fixes #46

* changing version to 0.4 to prepare for pypi push
* fixed license typo
* had to add `long_description_content_type="text/markdown"` to render content better in the pypi GUI

```
pallotron@pallotron-mbp:(master) ~/projects/fbtftp
$ python3 -m build
```

```
pallotron@pallotron-mbp:(master) ~/projects/fbtftp
$ python3 -m twine upload dist/*
Uploading distributions to https://upload.pypi.org/legacy/
Enter your username: pallotron
Enter your password:
Uploading fbtftp-0.4-py3-none-any.whl
100%|█████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████| 27.2k/27.2k [00:02<00:00, 11.3kB/s]
Uploading fbtftp-0.4.tar.gz
100%|█████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████| 35.0k/35.0k [00:01<00:00, 25.1kB/s]

View at:
https://pypi.org/project/fbtftp/0.4/
[Exit code 0 @ 09:43:34]
```

Pull Request resolved: #47

Reviewed By: martelli

Differential Revision: D27851016

Pulled By: pallotron

fbshipit-source-id: 8dd9190c28cbd57367c4791cd5aa6da11f9f95dc

Author: pallotron

setup.py

@@ -29,15 +29,16 @@ def run_tests(self):
 
 setup(
     name="fbtftp",
-    version="0.2",
+    version="0.4",
     description="A python3 framework to build dynamic TFTP servers",
     long_description=long_description,
+    long_description_content_type="text/markdown",
     author="Angelo Failla",
     author_email="pallotron@fb.com",
     license="BSD",
     classifiers=[
         "Development Status :: 5 - Production/Stable",
-        "License :: OSI Approved :: MIT icense",
+        "License :: OSI Approved :: MIT License",
         "Operating System :: POSIX :: Linux",
         "Programming Language :: Python :: 3 :: Only",
         "Programming Language :: Python :: 3.5",