Fix links in README (#40)

"en/latest" was missing

Author: leezu

README.rst

@@ -181,9 +181,9 @@ Project details
 tmux support    1.8, 1.9a, 2.0, 2.1, 2.2, 2.3, 2.4
 python support  2.7, >= 3.3, pypy, pypy3
 Source          https://github.com/tony/libtmux
-Docs            http://libtmux.git-pull.com
-API             http://libtmux.git-pull.com/api.html
-Changelog       http://libtmux.git-pull.com/history.html
+Docs            https://libtmux.git-pull.com
+API             https://libtmux.git-pull.com/en/latest/api.html
+Changelog       https://libtmux.git-pull.com/en/latest/history.html
 Issues          https://github.com/tony/libtmux/issues
 Travis          http://travis-ci.org/tony/libtmux
 Test Coverage   https://codecov.io/gh/tony/libtmux