Create CPM/FPKM fold change calculation output for files

[slsevilla]

Request:

Solution:
I've instructed Yuanyuan that negative controls should not be used as the 'background' of MANORM and that it is not possible to perform MANORM without normalization. She has requested then that code be added to perform CPM/FPKM fold change calculations between her negative controls and positive controls.

To do this we'll need to add a third option to differential analysis (IE "CPM"):

• Add comment notes to config/config.yaml under the "DEmethod"
• Create new manifest under manifest/contrasts_example_cpm.tsv. Column headers should be identified (IE "Sample,NegControl")
• Create script to perform the calculations
• Create elif statement to expand beyond MANORM/DIFFBIND to handle new rules

[slsevilla]

Do we still need to handle this @wilfriedguiblet ?