Bump approvaltests from 9.3.0 to 15.6.0#140

dependabot[bot] wants to merge 1 commit intomasterLearnWithLlew/DuplicationKata.java:masterfrom

dependabot/maven/com.approvaltests-approvaltests-15.6.0LearnWithLlew/DuplicationKata.java:dependabot/maven/com.approvaltests-approvaltests-15.6.0Copy head branch name to clipboard