Switch update_rel to just be a singular function

Instead of /pods-api/<podid>/update_rel you now just call /pods-api/update_rel and pass the same array we were already
passing that contains all the required info.  If you want to only update relationships for one specific pod then make
sure the array only contains info about that array

This should require a version bump so pods-deploy can say it requires > version X
Merge pull request #13 from jamesgol/changerel

Switch update_rel to just be a singular function
version 0.2.3
update readme.txt for 0.2.3