MAINT: Set version from 0_6_0 to 0_7_0 and updated release notes accordingly.
MAINT: Set version from 0_6_0 to 0_7_0 and updated release notes accordingly.

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