Removed OrderedDict from doctests.
Removed OrderedDict from doctests.

Since OrderedDict is not available in Python 2.6, remove it from the
doctests.

laijingtao/landlab,csherwood-usgs/landlab,landlab/landlab,Carralex/landlab,amandersillinois/landlab,ManuSchmi88/landlab,SiccarPoint/landlab,RondaStrauch/landlab,RondaStrauch/landlab,SiccarPoint/landlab,RondaStrauch/landlab,Carralex/landlab,cmshobe/landlab,amandersillinois/landlab,ManuSchmi88/landlab,cmshobe/landlab,landlab/landlab,Carralex/landlab,landlab/landlab,laijingtao/landlab,csherwood-usgs/landlab,cmshobe/landlab,ManuSchmi88/landlab