Clearer message for kallisto with single-end reads.
Clearer message for kallisto with single-end reads.

Closes #2491. Thanks to @davidmasica for bringing this up and for
checking to see if a) kallisto produces fusion calls with single-end
reads and if other tools generally support fusion calls from single-end
reads.

chapmanb/bcbio-nextgen,a113n/bcbio-nextgen,lbeltrame/bcbio-nextgen,vladsaveliev/bcbio-nextgen,a113n/bcbio-nextgen,vladsaveliev/bcbio-nextgen,a113n/bcbio-nextgen,vladsaveliev/bcbio-nextgen,chapmanb/bcbio-nextgen,chapmanb/bcbio-nextgen,lbeltrame/bcbio-nextgen,lbeltrame/bcbio-nextgen