Bump org.assertj:assertj-parent-pom from 2.2.17 to 2.2.18 (#204)

* Bump org.assertj:assertj-parent-pom from 2.2.17 to 2.2.18

Bumps [org.assertj:assertj-parent-pom](https://github.com/assertj/assertj-maven-parent-pom) from 2.2.17 to 2.2.18.
- [Commits](assertj/assertj-parent-pom@assertj-parent-pom-2.2.17...assertj-parent-pom-2.2.18)

---
updated-dependencies:
- dependency-name: org.assertj:assertj-parent-pom
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

* Fixes issue with compiling project for JDK8

---------

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Michał Chmielarz <[email protected]>

pom.xml

@@ -6,7 +6,7 @@
     <parent>
         <groupId>org.assertj</groupId>
         <artifactId>assertj-parent-pom</artifactId>
-        <version>2.2.17</version>
+        <version>2.2.18</version>
     </parent>
 
     <artifactId>assertj-vavr</artifactId>
@@ -132,18 +132,14 @@
         </dependency>
     </dependencies>
 
+    <properties>
+        <maven.compiler.release>8</maven.compiler.release>
+        <maven.compiler.source>8</maven.compiler.source>
+        <maven.compiler.target>8</maven.compiler.target>
+    </properties>
+
     <build>
         <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <configuration>
-                    <source>1.8</source>
-                    <target>1.8</target>
-                    <encoding>${project.build.sourceEncoding}</encoding>
-                </configuration>
-            </plugin>
-
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-javadoc-plugin</artifactId>