Update all seqtk tools to 1.3.1 re: bug fix + no implicit conversion

[jennaj]

MTS https://toolshed.g2.bx.psu.edu/view/iuc/seqtk/a09586d5149a

usegalaxy.org currently is several revisions behind, at 1.2.0

usegalaxy.eu has the most current version, 1.3.1

There is a bug fix with at least one of the tools (seqtk_sample 1.2.0 labels output datatype "data" instead of "fastqsanger"). The tools can also now handled compressed fastq without explicit conversion (no large hidden intermediate data).

Test histories for after update:

https://usegalaxy.org:/u/jen/h/test-seqtksample https://usegalaxy.eu:/u/jenj/h/test-seqtksample