DyNet v2.0.2

v 2.0.2 of DyNet includes the following improvements. Thanks to everyone who made them happen!

Done:

Better organized examples: #191
Full multi-device support: #952
Broadcasting standard elementwise operations: #776
Some refactoring: #522
Better profiling: #1088
Fix performance regression on autobatching: #974
Pre-compiled pip binaries
A bunch of other small functionality additions and bug fixes