If the file is already saved:
:!mv {file location} {new file location}
:e {new file location}
Example:
:!mv src/test/scala/myFile.scala src/test/scala/myNewFile.scala
:e src/test/scala/myNewFile.scala
Permission Requirements:
:!sudo mv src/test/scala/myFile.scala src/test/scala/myNewFile.scala
Save As:
:!mv {file location} {save_as file location}
:w
:e {save_as file location}
For Windows Unverified
:!move {file location} {new file location}
:e {new file location}