Revert "HOTFIX: Rolling back incorrect version change"

This reverts commit 3a4609eada2ee0bfbcce0f4127b6a5363ae528e5.
Revert "Preparing development version 1.2.1-SNAPSHOT"

This reverts commit 00316cc87983b844f6603f351a8f0b84fe1f6035.
Revert "Preparing Spark release v1.2.0-rc1"

This reverts commit 1056e9ec13203d0c51564265e94d77a054498fdb.