Fix resource directory location

This commit fixes the main resources directory location so that it also
works in a multi-projects setup.

Fixes gh-993
(cherry picked from commit a69f518)

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

@@ -185,7 +185,7 @@
 		<!-- Turn on filtering by default for application properties -->
 		<resources>
 			<resource>
-				<directory>src/main/resources</directory>
+				<directory>${basedir}/src/main/resources</directory>
 				<filtering>true</filtering>
 				<includes>
 					<include>**/application.yml</include>
@@ -193,7 +193,7 @@
 				</includes>
 			</resource>
 			<resource>
-				<directory>src/main/resources</directory>
+				<directory>${basedir}/src/main/resources</directory>
 				<excludes>
 					<exclude>**/application.yml</exclude>
 					<exclude>**/application.properties</exclude>