Added experimental test for pybombs installation on Ubuntu 15.04
diff --git a/.travis.yml b/.travis.yml
index 6f51506..b0df285 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,11 +3,13 @@
 language: ruby
 
 env:
+  - DOCKERFILE=dockerfiles/Ubuntu15_pybombs.docker IMGNAME=ubu15_pybombs-grgsm
   - DOCKERFILE=dockerfiles/DebianJessie.docker IMGNAME=debjess-grgsm
   # - DOCKERFILE=dockerfiles/Ubuntu14.docker IMGNAME=ubu14-grgsm
   - DOCKERFILE=dockerfiles/Ubuntu15.docker IMGNAME=ubu15-grgsm
   # - DOCKERFILE=dockerfiles/Kali.docker IMGNAME=kali-grgsm
 
+
 services:
   - docker