Moved Location (latitude, longitude) from User to Device Model

Signed-off-by: Ricardo Leitão <rleitao@lqd.io>
Add User and Event attributes sanitizer to clean invalid characters

Signed-off-by: Ricardo Leitão <rleitao@lqd.io>
Release Liquid v0.7.0-beta

Signed-off-by: Ricardo Leitão <rleitao@lqd.io>