Don't test against 3.1.0

Author: pesse

.travis.yml

@@ -27,7 +27,6 @@ env:
     - UTPLSQL_VERSION="v3.0.2"
     - UTPLSQL_VERSION="v3.0.3"
     - UTPLSQL_VERSION="v3.0.4"
-    - UTPLSQL_VERSION="v3.1.0"
     - UTPLSQL_VERSION="v3.1.1"
     - UTPLSQL_VERSION="v3.1.2"
     - UTPLSQL_VERSION="develop"