update docs

README.md

@@ -2,7 +2,7 @@
 
 JVCL (pronounced "Javicle") is a JSON DSL for audio/video transformations.
 
-Under the hood, it's all shell commands: `ffmpeg`, `mediainfo`, `sox`, and so on.
+Under the hood, it's all shell commands: `ffmpeg`, `mediainfo` and so on.
 
 JVCL provides higher-level semantics for working with these lower level tools.