0.7 fixes a bug that's pretty useful, i.e. inline functions no longer return explicit type definition.

Author: Reynold Xin <rxin@databricks.com>

Closes #5399 from rxin/style0.7 and squashes the following commits:

54c41b2 [Reynold Xin] Actually update the version.
09c759c [Reynold Xin] [SPARK-6750] Upgrade ScalaStyle to 0.7.