Add support for Oracle's R2DBC driver.

We support Oracle's experimental R2DBC driver by providing a dialect including bind markers. Since the driver is not yet available from Maven Central and it requires module-path support for ServiceLoader discovery, we need to apply a few workarounds including absence check for our integration tests.

See #230

pom.xml

@@ -215,6 +215,13 @@
 			<scope>test</scope>
 		</dependency>
 
+		<dependency>
+			<groupId>com.oracle.database.jdbc</groupId>
+			<artifactId>ojdbc11</artifactId>
+			<version>21.1.0.0</version>
+			<scope>test</scope>
+		</dependency>
+
 		<!-- R2DBC Drivers -->
 
 		<dependency>
@@ -287,6 +294,12 @@
 			</exclusions>
 		</dependency>
 
+		<dependency>
+			<groupId>org.testcontainers</groupId>
+			<artifactId>oracle-xe</artifactId>
+			<scope>test</scope>
+		</dependency>
+
 		<dependency>
 			<groupId>org.testcontainers</groupId>
 			<artifactId>postgresql</artifactId>
@@ -447,6 +460,22 @@
 				</plugins>
 			</build>
 		</profile>
+
+		<profile>
+			<id>java11</id>
+
+			<!-- enable once oracle-r2db is available from Maven Central
+			<dependencies>
+				<dependency>
+					<groupId>com.oracle.database.r2dbc</groupId>
+					<artifactId>oracle-r2dbc</artifactId>
+					<version>0.1.0</version>
+					<scope>test</scope>
+				</dependency>
+			</dependencies>
+
+			-->
+		</profile>
 	</profiles>
 
 	<repositories>