Remove deps.rs badge from README.md

Unfortunately it seems that deps.rs is not maintained anymore (deps-rs/deps.rs#40), and it has failed to keep up-to-date with the latest crates.io API, which has prevented it from analysing dependencies. It is potentially worth removing the badge until such a time that the leadership of the deps.rs project is clarified and changes are deployed.

README.md

@@ -1,7 +1,6 @@
 # printpdf
 
 [![Travis CI](https://travis-ci.org/fschutt/printpdf.svg?branch=master)](https://travis-ci.org/fschutt/printpdf) [![Appveyor](https://ci.appveyor.com/api/projects/status/2ioc0wopm5a8ixgm?svg=true)](https://ci.appveyor.com/project/fschutt/printpdf)
-[![Dependencies](https://deps.rs/repo/github/fschutt/printpdf/status.svg)](https://deps.rs/repo/github/fschutt/printpdf)
 
 `printpdf` is a library designed for creating printable PDF documents.