Markdown-up

- [aa13098](https://github.com/craigahobbs/markdown-up-py/commit/aa13098) - fix command-line opening of html files

- [5c5d3ae](https://github.com/craigahobbs/markdown-up-py/commit/5c5d3ae)
- call webbrowser.open directly and don't worry about blocking because any browser that does block won't work anyway (e.g. lynx)
- set gunicorn workers to 2 to fix safari issues

- [f9fdbae](https://github.com/craigahobbs/markdown-up-py/commit/f9fdbae) - use documented gunicorn standalone application

- [990ff3d](https://github.com/craigahobbs/markdown-up-py/commit/990ff3d) - improve reliability of browser launch

- [44f4c4b](https://github.com/craigahobbs/markdown-up-py/commit/44f4c4b) - improve gunicorn integration

- [fba39db](https://github.com/craigahobbs/markdown-up-py/commit/fba39db) - use gunicorn to host wsgi application to fix macos safari