Update versions for Fastqc, Fastq Screen & MultiQC in QC pipeline

[pjbriggs]

Proposal to update the versions of Fastqc, Fastq Screen and MultiQC in the QC pipeline:

• Fastqc: latest is 0.12.1, see https://www.bioinformatics.babraham.ac.uk/projects/fastqc/
• Fastq Screen: latest is 0.15.3, see https://github.com/StevenWingett/FastQ-Screen/releases
• MultiQC: latest is 1.21, see https://multiqc.info/