Remove snapshot repos from starter parent

Fixes gh-419

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

@@ -335,15 +335,4 @@
 			</plugins>
 		</pluginManagement>
 	</build>
-	<repositories>
-		<!-- TODO: remove this once all milestone dependencies are removed -->
-		<repository>
-			<id>spring-milestones</id>
-			<name>Spring Milestones</name>
-			<url>http://repo.spring.io/milestone</url>
-			<snapshots>
-				<enabled>false</enabled>
-			</snapshots>
-		</repository>
-	</repositories>
 </project>