Upgrade to Snakeyaml 1.19

Closes gh-10678

Author: wilkinsona

spring-boot-project/spring-boot-dependencies/pom.xml

@@ -139,7 +139,7 @@
 		<servlet-api.version>3.1.0</servlet-api.version>
 		<simple-json.version>1.1.1</simple-json.version>
 		<slf4j.version>1.7.25</slf4j.version>
-		<snakeyaml.version>1.18</snakeyaml.version>
+		<snakeyaml.version>1.19</snakeyaml.version>
 		<solr.version>6.6.2</solr.version>
 		<spring.version>5.0.1.BUILD-SNAPSHOT</spring.version>
 		<spring-amqp.version>2.0.0.RELEASE</spring-amqp.version>