Runtime error in Plot() - parameter name mixup?

[Rickard Westman]

Calls to Plot() seem to cause a runtime error:

  Python 2.7.15+ (default, Nov 27 2018, 23:36:35)
  [GCC 7.3.0] on linux2
  Type "help", "copyright", "credits" or "license" for more information.
  >>> from gasp import *
  >>>
  >>> begin_graphics(100, 100)
  >>> Plot((50, 50))
  Traceback (most recent call last):
    File "<stdin>", line 1, in <module>
    File "/usr/lib/python2.7/dist-packages/gasp/api.py", line 176, in __init__
      except: raise backend.GaspException("center is not in (x,y) format")
  gasp.backend.GaspException: 'center is not in (x,y) format'

Looking at line 176, there seems to be a mismatch between the reference to "center" and the actual name of the __init__ method parameter, which is "pos". Fixing this (patch attached) does seem to make things work.

Additional info as per reporting guidelines:

lsb-release -rd:
  Description: Ubuntu 18.04.3 LTS
  Release: 18.04

apt-cache policy python-gasp:
  python-gasp:
    Installed: 0.3.4-2
    Candidate: 0.3.4-2
    Version table:
   *** 0.3.4-2 500
          500 http://se.archive.ubuntu.com/ubuntu bionic/universe amd64 Packages
          500 http://se.archive.ubuntu.com/ubuntu bionic/universe i386 Packages
          100 /var/lib/dpkg/status

What I expected to happen: Not getting a runtime error, since I believe the invocation of Plot() is correct.

What happened instead: Got a runtime error.