Wd purge

[WardDeb]

• purge unneeded config settings (closes purge 'old_dirs' functionality #251, closes restructure 'prepare' rule #192)
• pandas and dominate included as requirements
• Simplify and make email more clear
• email includes offload, processing and periphery dir status (closes disk space status #201)
• scan_multiqc deprecated in favor of get_qc, which gets metrics from pycoqc and kraken report directly (closes scan_multiqc updates #249)
• email includes number of expected flow cells per project (closes Include an 'expected flowcells' / project #252)
• email includes % reads with q score above 18 (closes return % reads with Phred > 18 #202)
• flow cells are processed in order of ascending dates (closes flow cell finder sorted flowcells #253)
• actions set up for linting, installation and conda envs (#closes pytests #145)
• Includes support for multiplexed data (closes properly deal with multiplexed data #245 )
• Logs set and 'tee'd where appropriate, though not everywhere due to the burial of stdout/stderr in snakemake. (closes tee logs #241)