It would be nice to warn when using "ancestor_id" that the page isn't found and should be created

[seburdin]

Is your feature request related to a problem? Please describe.
I tried to use the ancestor_id feature for confluence publishing but got the error

Finding Root Page...

In Publisher.php line 125:
                                                                               
  You must at least specify a `root_id` or `ancestor_id` in your confluence c  
  onfiguration.                                                                

Describe the solution you'd like
Throw an exception here :

daux.io/libs/Format/Confluence/Publisher.php

Line 116 in 5190743

}

to say the page wasn't found and should be created manually

[seburdin]

After creating the ancestor page manually, ancestor tag still doesn't work and shows the same error in Publisher.php line 125. Only root_id tag seems to work.

[onigoetz]

This change has been released in 0.20.1