test: Switched from Hamcrest to AssertJ

Author: quintesse

pom.xml

@@ -31,7 +31,7 @@
         <maven.compiler.source>8</maven.compiler.source>
         <maven.compiler.target>8</maven.compiler.target>
         <junit.version>5.8.2</junit.version>
-        <hamcrest.version>2.2</hamcrest.version>
+        <assertj.version>3.21.0</assertj.version>
         <spotless.version>2.12.2</spotless.version>
         <google-java-format.version>1.7</google-java-format.version>
     </properties>
@@ -44,9 +44,9 @@
             <scope>test</scope>
         </dependency>
         <dependency>
-            <groupId>org.hamcrest</groupId>
-            <artifactId>hamcrest-library</artifactId>
-            <version>${hamcrest.version}</version>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
             <scope>test</scope>
         </dependency>
     </dependencies>