Fix JSON output not printing newline (#1091)

Author: silvanocerza

Diff for: cli/feedback/feedback.go

@@ -118,7 +118,7 @@ func (fb *Feedback) printJSON(v interface{}) {
 	if d, err := json.MarshalIndent(v, "", "  "); err != nil {
 		fb.Errorf("Error during JSON encoding of the output: %v", err)
 	} else {
-		fmt.Fprint(fb.out, string(d))
+		fmt.Fprintf(fb.out, "%v\n", string(d))
 	}
 }
 

Diff for: test/test_board.py

@@ -442,7 +442,7 @@ def test_board_details(run_command):
     # Test board listall with and without showing hidden elements
     result = run_command("board listall MIPS --format json")
     assert result.ok
-    assert result.stdout == "{}"
+    assert result.stdout == "{}\n"
 
     result = run_command("board listall MIPS -a --format json")
     assert result.ok