Replace date with version and release from README
Replace date with version and release from README

CHANGELOG has the date.

Bug: webm:1752
Change-Id: I2888ce2afed8619f043eee1e9ca23bdf9d75e607

ShiftMediaProject/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx,webmproject/libvpx,webmproject/libvpx,webmproject/libvpx