Expand {version} variable in reference documentation.

Fixes gh-19.

src/main/asciidoc/reference/dependencies.adoc

@@ -5,14 +5,14 @@ The easiest way to find compatible versions of Spring Vault dependencies is by r
 
 .Using the Spring Vault BOM
 ====
-[source, xml]
+[source, xml, subs="verbatim,attributes"]
 ----
 <dependencyManagement>
   <dependencies>
     <dependency>
       <groupId>org.springframework.vault</groupId>
       <artifactId>spring-vault-dependencies</artifactId>
-      <version>${version}</version>
+      <version>{version}</version>
       <scope>import</scope>
       <type>pom</type>
     </dependency>

src/main/asciidoc/reference/getting-started.adoc

@@ -12,7 +12,7 @@ Then add the following to `pom.xml` dependencies section.
 
 .Using the Spring Vault BOM
 ====
-[source,xml]
+[source,xml,subs="verbatim,attributes"]
 ----
 <dependencies>