title: I can't upgrade from adb version 1.0.29
body: <p>I'm trying to interface my nexus 7 with my linux mint machine. The device always shows as offline. I understand that this problem comes from having an adb older than 1.0.31. I keep installing the platform tools rev 21.1 which as of last month is the newest version which should install adb 1.0.31, but every time I run the command 'adb version' it comes back saying it is version 1.0.29. Is there another way to get it to upgrade?</p>