Delete table if the test fails (#331)

Author: billyjacobson

bigtable/hbase/snippets/src/main/java/com/example/cloud/bigtable/helloworld/HelloWorld.java

@@ -132,6 +132,11 @@ private static void doHelloWorld(String projectId, String instanceId) {
     } catch (IOException e) {
       System.err.println("Exception while running HelloWorld: " + e.getMessage());
       e.printStackTrace();
+      if (admin.tableExists(tableName.getName())) {
+        print("Cleaning up table");
+        admin.disableTable(table.getName());
+        admin.deleteTable(table.getName());
+      }
       System.exit(1);
     }