Added devil-nightly travis badge.

README.md

@@ -1,6 +1,8 @@
-[![Build Status](https://travis-ci.org/diasurgical/devilution.svg?branch=master)](https://travis-ci.org/diasurgical/devilution)
+Devilution: [![Build Status](https://travis-ci.org/diasurgical/devilution.svg?branch=master)](https://travis-ci.org/diasurgical/devilution)
 [![Build status](https://ci.appveyor.com/api/projects/status/ssk0xjhoka1uu940?svg=true)](https://ci.appveyor.com/project/galaxyhaxz/devilution)
 
+Nightly: [![Build Status](https://travis-ci.com/diasurgical/devil-nightly.svg?branch=master)](https://travis-ci.com/diasurgical/devil-nightly)
+
 [Discord](https://discord.gg/XEKDxHK)
 
 # Devilution