Text results position changed in PicketFence.publish_pdf

[LuisOlivaresJ]

Regarding issue #453

As can be see in line 40 from PylinacCanvas class

https://github.com/jrkerns/pylinac/blob/5894520e90d45d74a1a1d184eeed0121a2238afd/pylinac/core/pdf.py#L40

by default, metadata location is (2, 25.5). That is why the superposition when we call canvas.add_text(..., location = (1.5, 25), ...) in line 982 from picketfence.py

https://github.com/jrkerns/pylinac/blob/5894520e90d45d74a1a1d184eeed0121a2238afd/pylinac/picketfence.py#L981-L983

The new location to (1.5, 22) gives the posibility to show up to 7 metadata rows

[jrkerns]

Looks good. thanks