Update external FS page with personal contributions (#65)

* Add `fs.smbfs` and `fs.sshfs`
* Add CI badge in filesystem section header

Author: althonos

docs/source/external.rst

@@ -3,7 +3,24 @@ External Filesystems
 
 The following filesystems work with the FS interface, but are not built-in the the fs module. Please see the documentation for how to install them.
 
-WebDAV
-------
+SSH |ci ssh|
+------------
+`fs.sshfs <https://pypi.python.org/pypi/fs.sshfs/>`_ implements a Pyfilesystem2 filesystem running over the `SSH <https://en.wikipedia.org/wiki/Secure_Shell>`_ protocol, using `paramiko <https://pypi.python.org/pypi/paramiko>`_.
 
-`fs.webdavfs <https://pypi.python.org/pypi/fs.webdavfs/>`_ implements the `WebdavFS <https://en.wikipedia.org/wiki/WebDAV>`_ protocol.
+.. |ci ssh| image:: https://img.shields.io/travis/althonos/fs.sshfs/master.svg
+   :target: https://travis-ci.org/althonos/fs.sshfs/branches
+
+SMB |ci smb|
+------------
+`fs.smbfs <https://pypi.python.org/pypi/fs.smbfs/>`_ implements a Pyfilesystem2 filesystem running over the `SMB <https://en.wikipedia.org/wiki/Server_Message_Block>`_ protocol, using `pysmb <https://pypi.python.org/pypi/pysmb>`_.
+
+.. |ci smb| image:: https://img.shields.io/travis/althonos/fs.smbfs/master.svg
+   :target: https://travis-ci.org/althonos/fs.smbfs/branches
+
+
+WebDAV |ci webdav|
+------------------
+`fs.webdavfs <https://pypi.python.org/pypi/fs.webdavfs/>`_ implements Pyfilesystem2 over the `WebDAV <https://en.wikipedia.org/wiki/WebDAV>`_ protocol.
+
+.. |ci webdav| image:: https://img.shields.io/travis/PyFilesystem/webdavfs/master.svg
+   :target: https://travis-ci.org/PyFilesystem/webdavfs/branches