FIX: adjusting the required numpy version to 1.7 due to recent changes in wradlib.vpr.
FIX: adjusting the required numpy version to 1.7 due to recent changes in wradlib.vpr.

wradlib/wradlib,kmuehlbauer/wradlib,heistermann/wradlib,wradlib/wradlib,heistermann/wradlib,kmuehlbauer/wradlib