Prepare for v3.2.0 release

This CL bumps the minor version of the BQJDBC driver. In a recently
merged PR[0], we added the ability to configure a default dataset
project id, which is used in conjunction with the dataset id to locate
unqualified table references. We added this new capability in a
backwards compatible manner.

[0] #201

pom.xml

@@ -4,7 +4,7 @@
        to a groupId that we have ownership over -->
   <groupId>com.google.looker-open-source</groupId>
   <artifactId>bqjdbc</artifactId>
-  <version>3.1.1</version>
+  <version>3.2.0</version>
   <name>Big Query over JDBC</name>
   <description>A simple JDBC driver, to reach Google's BigQuery</description>
   <properties>