Merge branch '1.5.x' into 2.0.x

Author: snicoll

spring-boot-project/spring-boot-docs/src/main/asciidoc/getting-started.adoc

@@ -39,8 +39,19 @@ configuration).
 [[getting-started-system-requirements]]
 == System Requirements
 Spring Boot {spring-boot-version} requires https://www.java.com[Java 8 or 9] and
-{spring-reference}[Spring Framework {spring-version}] or above. Explicit build support is
-provided for Maven 3.2+ and Gradle 4.
+{spring-reference}[Spring Framework {spring-version}] or above.
+
+Explicit build support is provided for the following build tools:
+
+|===
+|Build Tool |Version
+
+|Maven
+|3.2+
+
+|Gradle
+|4.x
+|===