Update varius deps and change to use virtual snapshot repo

- Data Flow UI 1.6.0.RC1
- Deployer 1.3.3.RELEASE
- Skipper 1.0.8.RELEASE
- Scheduler SPI 1.0.0.RC1

Perhaps due to a bad skipper release process, changed spring-snapshots repo
from http://repo.spring.io/libs-snapshot-local to http://repo.spring.io/libs-snapshot

Author: markpollack

pom.xml

@@ -27,12 +27,12 @@
 	<properties>
 		<java.version>1.8</java.version>
 		<javadoc.opts>-Xdoclint:none</javadoc.opts>
-		<spring-cloud-dataflow-ui.version>1.6.0.M2</spring-cloud-dataflow-ui.version>
+		<spring-cloud-dataflow-ui.version>1.6.0.RC1</spring-cloud-dataflow-ui.version>
 
-		<spring-cloud-deployer.version>1.3.4.BUILD-SNAPSHOT</spring-cloud-deployer.version>
+		<spring-cloud-deployer.version>1.3.3.RELEASE</spring-cloud-deployer.version>
 		<spring-cloud-deployer-local.version>1.3.7.RELEASE</spring-cloud-deployer-local.version>
 
-		<spring-cloud-skipper.version>1.0.8.BUILD-SNAPSHOT</spring-cloud-skipper.version>
+		<spring-cloud-skipper.version>1.0.8.RELEASE</spring-cloud-skipper.version>
 
 		<spring-cloud-task.version>1.2.3.RELEASE</spring-cloud-task.version>
 
@@ -41,7 +41,7 @@
 		     release versions -->
 		<spring-cloud.version>Edgware.SR4</spring-cloud.version>
 
-		<spring-cloud-scheduler-spi.version>1.0.0.M2</spring-cloud-scheduler-spi.version>
+		<spring-cloud-scheduler-spi.version>1.0.0.RC1</spring-cloud-scheduler-spi.version>
 
 		<spring-cloud-common-security-config.version>1.0.2.RELEASE</spring-cloud-common-security-config.version>
 
@@ -303,7 +303,7 @@
 				<repository>
 					<id>spring-snapshots</id>
 					<name>Spring Snapshots</name>
-					<url>http://repo.spring.io/libs-snapshot-local</url>
+					<url>http://repo.spring.io/libs-snapshot</url>
 					<snapshots>
 						<enabled>true</enabled>
 					</snapshots>