tests: enable Connection API ITs (#309)

* tests: enable Connection API ITs

The abstract base class for all Connection API integration tests were marked with
category IntegrationTest, while all concrete subclasses were marked with
ParallelIntegrationTest. This caused them to be excluded from the CI builds.

* chore: run formatter

Author: olavloite

google-cloud-spanner/src/test/java/com/google/cloud/spanner/connection/ITAbstractSpannerTest.java

@@ -19,7 +19,6 @@
 import com.google.cloud.spanner.Database;
 import com.google.cloud.spanner.ErrorCode;
 import com.google.cloud.spanner.GceTestEnvConfig;
-import com.google.cloud.spanner.IntegrationTest;
 import com.google.cloud.spanner.IntegrationTestEnv;
 import com.google.cloud.spanner.ResultSet;
 import com.google.cloud.spanner.SpannerExceptionFactory;
@@ -43,13 +42,11 @@
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.ClassRule;
-import org.junit.experimental.categories.Category;
 
 /**
  * Base class for integration tests. This class is located in this package to be able to access
  * package-private methods of the Connection API
  */
-@Category(IntegrationTest.class)
 public abstract class ITAbstractSpannerTest {
   protected class ITConnectionProvider implements GenericConnectionProvider {
     public ITConnectionProvider() {}