fixed two tests
Merge pull request #102 from jdegoes/master

fixed two tests and one bug
move library tests to the correct files
move tests to correctly-named files
split pipeline tests in to merging tests and exprop tests
break out supporting code from pipeline.scala and merge.scala
move mergePatch tests to the correct file
move Reshape merging logic to merge.scala
rename merge() function
Merge branch 'master' of github.com:slamdata/slamengine into pipeline-cleanup
Merge pull request #108 from mossprescott/pipeline-cleanup

Pipeline cleanup
capture exceptions thrown by the MongoDB driver
remove debug print
default debug level to 1 (the old behavior)
capture log and detailedLog from backend; print one or the other depending on debugLevel
use scalaz.Either.fromTryCatchNonFatal
feedback on REPL when setting debug level; extend Error
go back to Task.fail for evaluator errors

revert change to use \/ inside the Task
instead, fix the handling of failure in the backend to wrap the
exception with LoggedError
ADT for DebugLevel
clean up diff