Fix typo: gradew -> gradlew (#11)
Fix typo: gradew -> gradlew (#11)

Thank you very much for your project.
Worked perfectly without any issues.
I just noticed this typos in the readme.
cfig/Android_boot_image_editor,cfig/Android_boot_image_editor,cfig/Nexus_boot_image_editor,cfig/Android_boot_image_editor,cfig/Nexus_boot_image_editor,cfig/Android_boot_image_editor,cfig/Android_boot_image_editor,cfig/Nexus_boot_image_editor,cfig/Nexus_boot_image_editor,cfig/Android_boot_image_editor