Fix #300 by sorting output targets before uploading

[nigiord]

I modified awsf3/utils.py by adding a sorting step based on mtime before uploading the created target files. Previously, the files were uploaded in arbitrary order, which created some issues with workflow managers (like snakemake) that rely on the mtime to decide if a file need to be recomputed.

This commit can be tested using the following docker image: nigiord/tibanna-awsf:1.2.8-fd40332 (awsf_image option at job submission)

Merging this should allow to close issue #300.

[nigiord]

I synced the fork with the current version of Tibanna as it was getting quite old. Still no conflict with base branch as it simply adds a sorting step before uploading.

At this point I'm not sure this will be merged one day in master, but people who encounter the same issue and would like to use this workaround just have to use awsf_image=nigiord/tibanna-awsf:1.8.1-16cb036c in tibanna config.