upgrade postgres in travis

Signed-off-by: Penghui Liao <liaoishere@gmail.com>

.travis.yml

@@ -43,8 +43,8 @@ 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"
   - sh -c "if [ '$ORM_DRIVER' = 'sqlite' ]; then touch $TRAVIS_BUILD_DIR/orm_test.db; fi"
-  - sh -c "if [ $(go version) == *1.[5-9]* ]; then go get github.com/golang/lint/golint; golint ./...; fi"
-  - sh -c "if [ $(go version) == *1.[5-9]* ]; then go tool vet .; fi"
+  - sh -c "go get github.com/golang/lint/golint; golint ./...;"
+  - sh -c "go tool vet ."
   - mkdir -p res/var
   - ./ssdb/ssdb-server ./ssdb/ssdb.conf -d
 after_script:
@@ -58,4 +58,4 @@ script:
   - find . ! \( -path './vendor' -prune \) -type f -name '*.go' -print0 | xargs -0 gofmt -l -s
   - golint ./...
 addons:
-  postgresql: "9.4"
+  postgresql: "9.6"