Renamed tests.jl to runtests.jl

To comply with the new standard in
https://github.com/JuliaLang/julia/pull/6191
Merge pull request #34 from JuliaLang/rename

Renamed tests.jl to runtests.jl
fix Travis config
Update README.md
Update api.md

Add warning that this discusses a future API. Close #35
Merge remote-tracking branch 'upstream/master'
Start API adjustment.