Merge branch 'hotfix_issue19_compiling'

* hotfix_issue19_compiling:
  add go-ethereum to vendor to prevent incompatible go-ethereum interface

Merge branch 'hotfix_submitter_hang'

* hotfix_submitter_hang:
  choose simple strategy, drop current claim if a tx is not verified in time
  setting version to 0.2.1
  working rebroadcast tx
  add timeout to tx watcher

Merge pull request #8 from SmartPool/release-0.2.0

Release 0.2.0

Create LICENSE