Remove reference to spring-boot.version in the build

Closes gh-5014

Author: snicoll

spring-boot-dependencies/pom.xml

@@ -43,9 +43,6 @@
 		</developer>
 	</developers>
 	<properties>
-		<!-- Spring Boot -->
-		<spring-boot.version>1.4.0.BUILD-SNAPSHOT</spring-boot.version>
-		<!-- Third Party -->
 		<activemq.version>5.12.2</activemq.version>
 		<antlr2.version>2.7.7</antlr2.version>
 		<artemis.version>1.1.0</artemis.version>
@@ -2009,7 +2006,7 @@
 				<plugin>
 					<groupId>org.springframework.boot</groupId>
 					<artifactId>spring-boot-maven-plugin</artifactId>
-					<version>${spring-boot.version}</version>
+					<version>1.4.0.BUILD-SNAPSHOT</version>
 				</plugin>
 				<plugin>
 					<groupId>org.apache.maven.plugins</groupId>

spring-boot-samples/spring-boot-sample-ant/pom.xml

@@ -36,7 +36,7 @@
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-antlib</artifactId>
-			<version>1.3.3.BUILD-SNAPSHOT</version>
+			<version>1.4.0.BUILD-SNAPSHOT</version>
 		</dependency>
 	</dependencies>
 	<build>
@@ -83,7 +83,7 @@
 					<dependency>
 						<groupId>org.springframework.boot</groupId>
 						<artifactId>spring-boot-antlib</artifactId>
-						<version>${spring-boot.version}</version>
+						<version>1.4.0.BUILD-SNAPSHOT</version>
 					</dependency>
 				</dependencies>
 			</plugin>

spring-boot-starters/spring-boot-starter-parent/pom.xml

@@ -151,7 +151,6 @@
 				<plugin>
 					<groupId>org.springframework.boot</groupId>
 					<artifactId>spring-boot-maven-plugin</artifactId>
-					<version>${spring-boot.version}</version>
 					<executions>
 						<execution>
 							<goals>
@@ -171,7 +170,7 @@
 						<dependency>
 							<groupId>org.springframework.boot</groupId>
 							<artifactId>spring-boot-maven-plugin</artifactId>
-							<version>${spring-boot.version}</version>
+							<version>1.4.0.BUILD-SNAPSHOT</version>
 						</dependency>
 					</dependencies>
 					<configuration>