specific test for bowtie2, does not find the ref yet as it did with bowtie1, strange
with statement compatible with python 2.6.6
Correct new syntax to reference bowtie2 indexes within fastq_screen
Skip bowtie2 tests on travis since bowtie2 indexes are hard to find publickl
@guillermo-carrasco, memory_profiler 0.31 is already on PyPi, good job
Adding psutil, thanks @guillermo-carrasco
Merge pull request #114 from brainstorm/master

Bowtie2 site-specific tweaks for fastq_screen with Bowtie2