Statik

* Remove support for Python 2 in line with upcoming deprecation in 2020
* Update all dependencies to latest working versions
* Remove support for Python 3.5
* Update Netlify support with own internal deployment mechanism
* Update SFTP support with own internal deployment mechanism
* Make all output logging conform to the same standard, with the only difference
between normal output logging and verbose (`-v`) logging being the logging
level

* Merging 74 to better organise the growing list of CLI arguments.

* Minor fix to add missing `paramiko` dependency

* Merges 68
* Merges 73 to add SFTP upload functionality
* Updates dependency versions in `requirements.txt`
* Updates Markdown package integration to use new API

* Merging 65 to fix 64.

* Attempting to fix issues 50 and 63 - automatic translation of special Unicode characters
has now been turned off under the assumption that HTML output should be able to contain
the raw Unicode characters.