travis: test for mixed tool data_manager PR

if there is more than 1 changed repo (eg 1 tool and 1 data manager)
then planemo is called per repo, which fails for data manager because
the path to the xml is needed.

hence if the repo is in the data_managers directory the path to the
xml file is determined with an additional call to `planemo
ci_find_tools` and then used in the planemo test call.

.travis.yml

@@ -121,6 +121,11 @@ script:
         planemo test --galaxy_branch "$GALAXY_RELEASE" --galaxy_source "$GALAXY_REPO" $(cat changed_tools_chunk.list)
     elif [ -s changed_repositories_chunk.list ]; then
         while read -r DIR; do
-            planemo test --galaxy_branch "$GALAXY_RELEASE" --galaxy_source "$GALAXY_REPO" "$DIR"
+            if [[ "$DIR" =~ ^data_managers.* ]]; then
+                TESTPATH=$(planemo ci_find_tools "$DIR")
+            else
+                TESTPATH="$DIR"
+            fi
+            planemo test --galaxy_branch "$GALAXY_RELEASE" --galaxy_source "$GALAXY_REPO" "$TESTPATH"
         done < changed_repositories_chunk.list
     fi