sumaclust app controller added
moved cluster creation to sumaclust app controller
added option for multithreading
added exception to create an empty output file is input was empty for sumaclust
pep8 and coverage ran on code, changes made
Merge branch 'master' of https://github.com/biocore/brokit into add-sumaclust

merging with master upstream for latest changes
code review suggestions taken into account
Merge pull request #33 from ekopylova/add-sumaclust

App controller for SumaClust v1.0