Address release PR issues

[chaochaowong]

This PR address the release PR (#57) issues including (1) removing duplicated anonymous AWS S3 client setting and (2) fixing test profile reference configuration and test profile descriptions.

PR checklist

• This comment contains a description of changes (with reason).
• If you've fixed a bug or added code that should be tested, add tests!
• If you've added a new tool - have you followed the pipeline conventions in the contribution docs
• If necessary, also make a PR on the nf-core/pacvar branch on the nf-core/test-datasets repository.
• Make sure your code lints (nf-core pipelines lint).
• Ensure the test suite passes (nextflow run . -profile test,docker --outdir <OUTDIR>).
• Check for unexpected warnings in debug mode (nextflow run . -profile debug,test,docker --outdir <OUTDIR>).
• Usage Documentation in docs/usage.md is updated.
• Output Documentation in docs/output.md is updated.
• CHANGELOG.md is updated.
• README.md is updated (including new tool citations and authors/contributors).

[SPPearce]

Please update the changelog as well.
Note that I'm on vacation for the next week so won't be very responsive.

[chaochaowong]

Please update the changelog as well. Note that I'm on vacation for the next week so won't be very responsive.

Thank you for catching it. I updated the changelog.