[Fix] - Corrent the bugs when mergering multiple files
Merge branch 'master' of github.com:migocorp/athena
[Fix] - When key equals None, we should skip the output
[Feature] - Add a parameter to control inner join or not
[Fix] - Corrent the data type for is_inner
[Fix] - For idx_index, we should use idx-value to be the position for output, not idx-key
[Fix] - Due to the change of DataMerger, we need to do something
[Fix] - bugs for key separator of MigoDataMerger
[Fix] - critical bugs in del self.idx_index. We need to clone an object from self.idx_index not operate it directly
[Fix] - error happened when string join
[Fix] - Index Error of DataMergerFile
[Refactor] - Move the code from requires() to start() to decrease the complexity of parameter setting
[Fix] - 1. Typo - requrie --> requires 2. logic error in MigoTagging
[Refactor] - Enhance the performace when the join is inner criteria
[Test] - modify reduce tasks from 25 up to 50
Merge pull request #18 from migocorp/arpu_stickness_activeness

Arpu stickness activeness
[Fix] - The logic is wrong, correct it.
Merge branch 'master' of https://github.com/migocorp/athena
[Refactor] - Move the inner join checking to the header
[Fix] - Partition Bug