Add aws requirement to README

README.md

@@ -46,7 +46,7 @@ All Python dependencies are specified in `environment.yml`. For producing sequen
 alignments, you'll also need `kalign`, the [HH-suite](https://github.com/soedinglab/hh-suite), 
 and one of {`jackhmmer`, [MMseqs2](https://github.com/soedinglab/mmseqs2) (nightly build)} 
 installed on on your system. You'll need `git-lfs` to download OpenFold parameters. 
-Finally, some download scripts require `aria2c`.
+Finally, some download scripts require `aria2c` and `aws`.
 
 For convenience, we provide a script that installs Miniconda locally, creates a 
 `conda` virtual environment, installs all Python dependencies, and downloads