Add gitignore
Convert tabs to spaces and cleanup extraneous whitespace
Update aws sdk to 1.9.10
Use PutRecords to enable batching of sinks

- Uses a configuration option of `batchSize` to set size of batch
- Use PutRecords instead of PutRecord to send batched events
Catch and rethrow exceptions in sink process()
Use Preconditions to check for valid configuration
Use constants for default values in configuration
Update README to describe configuration options
Add precondition to check number of partitions
Update sink counter metrics