combiner: join two tables
combiner: refactor to Join transform
transforms: Join: linting errors
transforms: use iota for join types
transforms: add test for Left join
combiner: fix broken test TestTableTransformError
combiner: use go routine in Join
combiner: update join to use struct for cleaner enum behavior
Merge pull request #1 from nathanleiby/combiner

combiner: combine two tables via join or extend
transforms: add Reduce
sources: add gearman source
fix outdated CSV readme
transforms: add Concurrent
transforms: fix outdated documentation
transforms: concurrent -> concurrently
transforms: add Concat transform
transforms: don't test the same source for concat
transforms: clarify that we test order
Merge pull request #2 from azylman/concat

transforms: add Concat transform
source: gearman: update for new gearman interface