Add Limma analysis

[vksriharsha]

Paper: https://academic.oup.com/nar/article/43/7/e47/2414268

Other resources:
https://ucdavis-bioinformatics-training.github.io/2018-June-RNA-Seq-Workshop/thursday/DE.html

Success Criteria: Complete the workflow in the given Limma analysis workflow diagram: https://www.figma.com/file/Y8Q1zoSmUNmN2hehV1Oc16/Limma-Analysis-Workflow?node-id=0%3A1

MOG should facilitate the selection of genes, samples and groups and send it to the backend R script, which will execute the analysis and write the output diagrams and xls file to the result directory. MOG should be able to read these output files and open them up for users to view. If a timeout occurs, MOG should exit gracefully by displaying the R log.

The Sample R script file to execute limma analysis, and the sample raw data files are in the location: https://drive.google.com/drive/folders/14NMN0GoRVG4db6skx1EUE7e3fneekXSG?usp=sharing