fix assert_equal output in tests

Author: ekalinin

tests/test_helper.bash

@@ -2,8 +2,8 @@
 
 assert_equal() {
   if [ "$1" != "$2" ]; then
-    echo "expected: $1"
-    echo "actual:   $2"
+    echo "actual:     $1"
+    echo "expected:   $2"
     return 1
   fi
 }