Apply update.sh to .travis.yml

Author: tianon

.travis.yml

@@ -15,7 +15,6 @@ env:
   - VERSION=3.3 VARIANT=wheezy
   - VERSION=3.2 VARIANT=
   - VERSION=3.2 VARIANT=slim
-  - VERSION=3.2 VARIANT=alpine
   - VERSION=3.2 VARIANT=wheezy
   - VERSION=2.7 VARIANT=
   - VERSION=2.7 VARIANT=slim