Travis tests for v2.5.2

Author: GiovanniBussi

CHANGES/v2.5.md

@@ -172,7 +172,7 @@ For users:
   - Numpy is not required anymore at build time (though it is required at runtime for our tests).
   - Raw python arrays can be passed as an alternative to Numpy ndarrays.
 
-## Version 2.5.2 ()
+## Version 2.5.2 (coming soon)
 
 For users:
 - New shortcuts are available for selecting protein atoms: `@chi2-#`, `@chi3-#`,`@chi4-#` and `@chi5-#`