Add ability to write to Confluence

[wesley-dean-flexion]

As a QPP Engineer, so that I can automate the creation and maintenance of pages found in Confluence, I would like FCLI to be able to write to pages in Confluence.

Consider the following example:

./generate_qoe_report.py | fcli --confluence --update-page --page-id=123456789

This example is meant to demonstrate a workflow rather than any particular syntax or command line options.

Here, the results of running a report are piped to FCLI which would then update Confluence. This would allow offline or batch creation or updating of pages using logic from outside of Confluence; that is, it would provide a channel by which other sources may be indirectly integrated with Confluence.