Add support for .yaml file extensions

Apparently yaml.org prefers .yaml, but the internet seems
to be more aligned with .yml, so I guess we should support both
out of the box.

Fixes gh-675

spring-boot/src/main/java/org/springframework/boot/env/YamlPropertySourceLoader.java

@@ -27,7 +27,7 @@ import org.springframework.core.io.Resource;
 import org.springframework.util.ClassUtils;
 
 /**
- * Strategy to load '.yml' files into a {@link PropertySource}.
+ * Strategy to load '.yml' (or '.yaml') files into a {@link PropertySource}.
  * 
  * @author Dave Syer
  * @author Phillip Webb
@@ -36,7 +36,7 @@ public class YamlPropertySourceLoader implements PropertySourceLoader {
 
 	@Override
 	public String[] getFileExtensions() {
-		return new String[] { "yml" };
+		return new String[] { "yml", "yaml" };
 	}
 
 	@Override

spring-boot/src/test/java/org/springframework/boot/env/PropertySourcesLoaderTests.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2012-2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.env;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertTrue;
+
+/**
+ * @author Dave Syer
+ */
+public class PropertySourcesLoaderTests {
+
+	private PropertySourcesLoader loader = new PropertySourcesLoader();
+
+	@Test
+	public void test() {
+		assertTrue(this.loader.getAllFileExtensions().contains("yml"));
+		assertTrue(this.loader.getAllFileExtensions().contains("yaml"));
+		assertTrue(this.loader.getAllFileExtensions().contains("properties"));
+	}
+
+}

spring-boot/src/test/java/org/springframework/boot/env/YamlPropertySourceLoaderTests.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2012-2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.env;
+
+import org.junit.Test;
+import org.springframework.core.env.PropertySource;
+import org.springframework.core.io.ByteArrayResource;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+/**
+ * @author Dave Syer
+ */
+public class YamlPropertySourceLoaderTests {
+
+	private YamlPropertySourceLoader loader = new YamlPropertySourceLoader();
+
+	@Test
+	public void test() throws Exception {
+		PropertySource<?> source = this.loader.load("resource", new ByteArrayResource(
+				"foo:\n  bar: spam".getBytes()), null);
+		assertNotNull(source);
+		assertEquals("spam", source.getProperty("foo.bar"));
+	}
+
+}