Add test for Snapshot 0
Add test for Snapshot 0

Summary:
I ran into this assert when stress testing transactions.  It's pretty easy to repro.

Changing VersionSet::last_sequence_ to start at 1 seems pretty straightforward.  We would just need to change the 4 callers of SetLastSequence(), including recovery code.  I'd make this change myself, but I do not have enough time to test changes to recovery code-paths this week.  But checking in this test case (disabled) for future fixing.

Test Plan: n/a

Reviewers: yhchiang, kradhakrishnan, andrewkr, anthony, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D55311

SunguckLee/RocksDB,ryneli/rocksdb,bbiao/rocksdb,wenduo/rocksdb,tsheasha/rocksdb,Andymic/rocksdb,bbiao/rocksdb,facebook/rocksdb,tsheasha/rocksdb,jalexanderqed/rocksdb,jalexanderqed/rocksdb,SunguckLee/RocksDB,wenduo/rocksdb,OverlordQ/rocksdb,facebook/rocksdb,bbiao/rocksdb,hobinyoon/rocksdb,bbiao/rocksdb,flabby/rocksdb,facebook/rocksdb,wat-ze-hex/rocksdb,Andymic/rocksdb,ryneli/rocksdb,flabby/rocksdb,jalexanderqed/rocksdb,norton/rocksdb,vmx/rocksdb,OverlordQ/rocksdb,ryneli/rocksdb,jalexanderqed/rocksdb,bbiao/rocksdb,facebook/rocksdb,Andymic/rocksdb,ryneli/rocksdb,norton/rocksdb,jalexanderqed/rocksdb,flabby/rocksdb,wat-ze-hex/rocksdb,wenduo/rocksdb,SunguckLee/RocksDB,Andymic/rocksdb,wat-ze-hex/rocksdb,OverlordQ/rocksdb,SunguckLee/RocksDB,SunguckLee/RocksDB,vmx/rocksdb,SunguckLee/RocksDB,bbiao/rocksdb,wat-ze-hex/rocksdb,vmx/rocksdb,tsheasha/rocksdb,facebook/rocksdb,facebook/rocksdb,hobinyoon/rocksdb,tsheasha/rocksdb,hobinyoon/rocksdb,facebook/rocksdb,wenduo/rocksdb,wat-ze-hex/rocksdb,norton/rocksdb,vmx/rocksdb,vmx/rocksdb,SunguckLee/RocksDB,vmx/rocksdb,OverlordQ/rocksdb,norton/rocksdb,norton/rocksdb,hobinyoon/rocksdb,ryneli/rocksdb,wenduo/rocksdb,hobinyoon/rocksdb,vmx/rocksdb,OverlordQ/rocksdb,ryneli/rocksdb,Andymic/rocksdb,jalexanderqed/rocksdb,tsheasha/rocksdb,wat-ze-hex/rocksdb,wenduo/rocksdb,norton/rocksdb,flabby/rocksdb,tsheasha/rocksdb,ryneli/rocksdb,facebook/rocksdb,norton/rocksdb,wat-ze-hex/rocksdb,hobinyoon/rocksdb,wenduo/rocksdb,flabby/rocksdb,OverlordQ/rocksdb,Andymic/rocksdb,Andymic/rocksdb,tsheasha/rocksdb,jalexanderqed/rocksdb,SunguckLee/RocksDB,vmx/rocksdb,flabby/rocksdb,bbiao/rocksdb,hobinyoon/rocksdb,Andymic/rocksdb,flabby/rocksdb,wenduo/rocksdb,tsheasha/rocksdb,bbiao/rocksdb,hobinyoon/rocksdb,OverlordQ/rocksdb,wat-ze-hex/rocksdb,norton/rocksdb