To reproduce:

1. Create a new project
2. Create a new scene and add it to build settings
3. Go to File -> Save Project
4. Create a new folder in the Assets
5. Put the scene asset into the new folder
6. Go to File -> Save Project
7. Go to File -> Exit
8. Open the project's EditorBuildSettings.asset with a text editor
9. Observe that the path to the scene wasn't updated after moving the scene to another folder

Expected: the path to scene is updated in the EditorBuildSettings.asset when the scene is renamed or moved to another folder

Reproduced in 2017.2.3f1, 2017.3.2f1, 2017.4.2f2, 2017.4.3f1, 2018.1.0f2, 2018.2.0b4, 2018.3.0a1