v1.2.0

https://central.sonatype.com/artifact/io.github.malczuuu.problem4j/problem4j-core/1.2.0

1. Maven:

   <dependencies>
       <dependency>
           <groupId>io.github.malczuuu.problem4j</groupId>
           <artifactId>problem4j-core</artifactId>
           <version>1.2.0</version>
       </dependency>
   </dependencies>

2. Gradle (Kotlin DSL):

   dependencies {
       implementation("io.github.malczuuu.problem4j:problem4j-core:1.2.0")
   }

Added

• Add getExtensionMembers() method to complement existing extensions-manipulation methods.
• Make ProblemImpl#equals and ExtensionImpl#equals work with different implementations of Problem and Extension interfaces.

Fixed

• Do not add null values to extensions.

Changes: v1.1.1...v1.2.0