renaming

src/de/uni_passau/fim/seibt/gitwrapper/repo/Repository.java

@@ -86,7 +86,7 @@ public class Repository {
      *         the second {@link Commit}
      * @return the merge base or
      */
-    public Optional<Commit> mergeBase(Commit a, Commit b) {
+    public Optional<Commit> getMergeBase(Commit a, Commit b) {
 
         if (!(commits.values().contains(a) && commits.values().contains(b))) {
             LOG.warning(() -> "Both commits must be part of the repository to get a merge base for them.");