travis test uses env matrix

Signed-off-by: Lai Jiangshan <[email protected]>

Author: laijs

.travis.yml

@@ -1,11 +1,16 @@
 sudo: required
 dist: trusty
 
-language: c
+language: go
 
-matrix:
-  include:
-    - go: 1.7
+go:
+  - 1.8
+
+env:
+  - HYPER_EXEC_DRIVER=qemu    HYPER_STORAGE_DRIVER=aufs
+  - HYPER_EXEC_DRIVER=qemu    HYPER_STORAGE_DRIVER=rawblock
+  - HYPER_EXEC_DRIVER=libvirt HYPER_STORAGE_DRIVER=overlay
+  - HYPER_EXEC_DRIVER=libvirt HYPER_STORAGE_DRIVER=rawblock
 
 before_install:
   - sudo apt-get update -qq