Upgrade dependencies to current milestones

- Reactor Bismuth-M4
- Spring Framework 5.0.0.RC4
- Spring Data Kay-RC3
- Lettuce 5.0.0.RC2

gradle/dependency-management.gradle

@@ -1,8 +1,8 @@
 dependencyManagement {
 	imports {
-		mavenBom 'io.projectreactor:reactor-bom:Bismuth-BUILD-SNAPSHOT'
-		mavenBom 'org.springframework:spring-framework-bom:5.0.0.BUILD-SNAPSHOT'
-		mavenBom 'org.springframework.data:spring-data-releasetrain:Kay-BUILD-SNAPSHOT'
+		mavenBom 'io.projectreactor:reactor-bom:Bismuth-M4'
+		mavenBom 'org.springframework:spring-framework-bom:5.0.0.RC4'
+		mavenBom 'org.springframework.data:spring-data-releasetrain:Kay-RC3'
 		mavenBom 'org.springframework.security:spring-security-bom:5.0.0.BUILD-SNAPSHOT'
 	}
 
@@ -24,7 +24,7 @@ dependencyManagement {
 		dependency 'com.maxmind.geoip2:geoip2:2.3.1'
 		dependency 'commons-codec:commons-codec:1.10'
 		dependency 'edu.umd.cs.mtc:multithreadedtc:1.01'
-		dependency 'io.lettuce:lettuce-core:5.0.0.RC1'
+		dependency 'io.lettuce:lettuce-core:5.0.0.RC2'
 		dependency 'javax.servlet.jsp.jstl:javax.servlet.jsp.jstl-api:1.2.1'
 		dependency 'javax.servlet.jsp:javax.servlet.jsp-api:2.3.2-b02'
 		dependency 'javax.servlet:javax.servlet-api:3.1.0'

samples/boot/findbyusername/spring-session-sample-boot-findbyusername.gradle

@@ -1,6 +1,6 @@
 apply plugin: 'io.spring.convention.spring-sample-boot'
 
-ext['spring-data-releasetrain.version'] = 'Kay-BUILD-SNAPSHOT'
+ext['spring-data-releasetrain.version'] = 'Kay-RC3'
 
 dependencies {
 	compile project(':spring-session-data-redis')

samples/boot/redis-json/spring-session-sample-boot-redis-json.gradle

@@ -1,6 +1,6 @@
 apply plugin: 'io.spring.convention.spring-sample-boot'
 
-ext['spring-data-releasetrain.version'] = 'Kay-BUILD-SNAPSHOT'
+ext['spring-data-releasetrain.version'] = 'Kay-RC3'
 
 dependencies {
 	compile project(':spring-session-data-redis')

samples/boot/redis/spring-session-sample-boot-redis.gradle

@@ -1,6 +1,6 @@
 apply plugin: 'io.spring.convention.spring-sample-boot'
 
-ext['spring-data-releasetrain.version'] = 'Kay-BUILD-SNAPSHOT'
+ext['spring-data-releasetrain.version'] = 'Kay-RC3'
 
 dependencies {
 	compile project(':spring-session-data-redis')

samples/boot/websocket/spring-session-sample-boot-websocket.gradle

@@ -1,6 +1,6 @@
 apply plugin: 'io.spring.convention.spring-sample-boot'
 
-ext['spring-data-releasetrain.version'] = 'Kay-BUILD-SNAPSHOT'
+ext['spring-data-releasetrain.version'] = 'Kay-RC3'
 
 dependencies {
 	compile project(':spring-session-data-redis')