v0.2.2: NCBI changes and bugfixes

• fix for issue #53 (--maxmatch has no effect)
• fix to genbank_get_genomes_by_taxon.py to account for NCBI FTP location changes
• fixed issue #52 (local variable bug)
• fixed issued #49 (TETRA failure) and #51 (matplotlib bug)
• add several tests and support for codecov.io, landscape.io and Travis-CI
• removed requirement for rpy2
• moved scripts to bin/ subdirectory