fix travis.yml

.travis.yml

@@ -29,6 +29,7 @@ install:
   - go get golang.org/x/tools/cmd/vet
   - go get github.com/golang/lint/golint
   - go get github.com/ssdb/gossdb/ssdb
+  - go get github.com/astaxie/beego/cache
 before_script:
   - sh -c "if [ '$ORM_DRIVER' = 'postgres' ]; then psql -c 'create database orm_test;' -U postgres; fi"
   - sh -c "if [ '$ORM_DRIVER' = 'mysql' ]; then mysql -u root -e 'create database orm_test;'; fi"