chore: upgrade to Spring Boot 3

Spring Boot 3 made some changes to the way a library, such as this one,
notifies Spring Boot that it wants to be autoconfigured.

[Details of this change are in the release notes of version 2.7][1].

With this commit, a new versioning system for this package is proposed:
`<Spring Boot version>-<tradition semantic versioning>`. For example,
`3-1.0.2`. Why? The problem with only semantic versioning _and_
following Spring releases (especially those with breaking changes) is,
that it becomes unclear when to update to a new major version. Should we
do it when this library introduces a breaking change? Or when Spring
Boot does? To solve this, the version now consists of a leading digit,
indicating the Spring Boot version that this version works with,
followed by a semantic version of the library itself.

So, we now have `2-1.0.2`, working with Spring Boot 2, alongside
`3-1.0.2`, which works with Spring Boot 3. When a breaking change is
made to this library, we would signal that by bumping the versions to
`2-2.0.0` and `3-2.0.0`, respectively.

[1]: <https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-2.7-Release-Notes#changes-to-auto-configuration>

pom.xml

@@ -7,7 +7,7 @@
     <artifactId>cryptvault</artifactId>
     <packaging>jar</packaging>
     <name>cryptvault</name>
-    <version>1.0.2</version>
+    <version>3-1.0.2</version>
     <description>Versioned crypto library</description>
     <url>https://github.com/bolcom/cryptvault</url>
 
@@ -43,26 +43,26 @@
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-autoconfigure</artifactId>
-            <version>2.4.0</version>
+            <version>3.2.3</version>
             <scope>provided</scope>
         </dependency>
 
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>
-            <version>2.4.0</version>
+            <version>3.2.3</version>
             <scope>test</scope>
         </dependency>
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
-            <version>4.13.1</version>
+            <version>4.13.2</version>
             <scope>test</scope>
         </dependency>
         <dependency>
             <groupId>org.assertj</groupId>
             <artifactId>assertj-core</artifactId>
-            <version>3.18.1</version>
+            <version>3.25.3</version>
             <scope>test</scope>
         </dependency>
     </dependencies>

src/main/java/com/bol/config/CryptVaultAutoConfiguration.java

@@ -1,16 +1,16 @@
 package com.bol.config;
 
 import com.bol.crypt.CryptVault;
+import org.springframework.boot.autoconfigure.AutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.context.annotation.Bean;
-import org.springframework.context.annotation.Configuration;
 import org.springframework.stereotype.Component;
 
 import java.util.Base64;
 import java.util.List;
 
-@Configuration
+@AutoConfiguration
 @ConditionalOnProperty("cryptvault.keys[0].key")
 public class CryptVaultAutoConfiguration {
 

src/main/resources/META-INF/spring/org.springframework.boot.autoconfigure.AutoConfiguration.imports

@@ -0,0 +1 @@
+com.bol.config.CryptVaultAutoConfiguration