Add auto-configuration for reactive Redis

This commit provides an auto-configuration for reactive Redis and a
starter that provides Lettuce as Jedis doesn't support reactive
operations.

There are no support for reactive redis repositories at the moment so
only a `ReactiveRedisTemplate` is auto-configured if necessary.

Closes gh-8053

spring-boot-starters/pom.xml

@@ -38,6 +38,7 @@
 		<module>spring-boot-starter-data-mongodb-reactive</module>
 		<module>spring-boot-starter-data-neo4j</module>
 		<module>spring-boot-starter-data-redis</module>
+		<module>spring-boot-starter-data-redis-reactive</module>
 		<module>spring-boot-starter-data-rest</module>
 		<module>spring-boot-starter-data-solr</module>
 		<module>spring-boot-starter-freemarker</module>

spring-boot-starters/spring-boot-starter-data-redis-reactive/pom.xml

@@ -0,0 +1,71 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-starters</artifactId>
+		<version>2.0.0.BUILD-SNAPSHOT</version>
+	</parent>
+	<artifactId>spring-boot-starter-data-redis-reactive</artifactId>
+	<name>Spring Boot Data Redis Reactive Starter</name>
+	<description>Starter for using Redis key-value data store with Spring Data Redis
+		reactive and the Lettuce client</description>
+	<url>http://projects.spring.io/spring-boot/</url>
+	<organization>
+		<name>Pivotal Software, Inc.</name>
+		<url>http://www.spring.io</url>
+	</organization>
+	<properties>
+		<main.basedir>${basedir}/../..</main.basedir>
+	</properties>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.data</groupId>
+			<artifactId>spring-data-redis</artifactId>
+			<exclusions>
+				<exclusion>
+					<groupId>org.slf4j</groupId>
+					<artifactId>jcl-over-slf4j</artifactId>
+				</exclusion>
+			</exclusions>
+		</dependency>
+		<dependency>
+			<groupId>io.lettuce</groupId>
+			<artifactId>lettuce-core</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.commons</groupId>
+			<artifactId>commons-pool2</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>io.projectreactor</groupId>
+			<artifactId>reactor-core</artifactId>
+		</dependency>
+	</dependencies>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.basepom.maven</groupId>
+				<artifactId>duplicate-finder-maven-plugin</artifactId>
+				<executions>
+					<execution>
+						<id>duplicate-dependencies</id>
+						<phase>validate</phase>
+						<goals>
+							<goal>check</goal>
+						</goals>
+						<configuration>
+							<ignoredResourcePatterns>
+								<ignoredResourcePattern>changelog.txt</ignoredResourcePattern>
+							</ignoredResourcePatterns>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+</project>

spring-boot-starters/spring-boot-starter-data-redis-reactive/src/main/resources/META-INF/spring.provides

@@ -0,0 +1 @@
+provides: spring-data-redis,lettuce-core