Files should be overwritten

[io7m]

xstructural: Main: ERROR: java.nio.file.FileAlreadyExistsException: /builds/data/workspace/com.io7m.calino/com.io7m.calino.specification/target/epub/epub/META-INF/container.xml
com.io7m.xstructural.api.XSProcessorException: java.nio.file.FileAlreadyExistsException: /builds/data/workspace/com.io7m.calino/com.io7m.calino.specification/target/epub/epub/META-INF/container.xml
	at com.io7m.xstructural.vanilla.internal.XSEPUBCreator.execute(XSEPUBCreator.java:261)
	at com.io7m.xstructural.vanilla.internal.XSProcessor.execute(XSProcessor.java:82)
	at com.io7m.xstructural.cmdline.XSCommandTransformEPUB.execute(XSCommandTransformEPUB.java:100)
	at com.io7m.xstructural.cmdline.Main.run(Main.java:116)
	at com.io7m.xstructural.cmdline.MainExitless.main(MainExitless.java:47)
	at org.codehaus.mojo.exec.ExecJavaMojo$1.run(ExecJavaMojo.java:254)
	at java.base/java.lang.Thread.run(Thread.java:833)
Caused by: java.nio.file.FileAlreadyExistsException: /builds/data/workspace/com.io7m.calino/com.io7m.calino.specification/target/epub/epub/META-INF/container.xml
	at java.base/sun.nio.fs.UnixException.translateToIOException(UnixException.java:94)
	at java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:106)
	at java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:111)
	at java.base/sun.nio.fs.UnixFileSystemProvider.newByteChannel(UnixFileSystemProvider.java:219)
	at java.base/java.nio.file.spi.FileSystemProvider.newOutputStream(FileSystemProvider.java:484)
	at java.base/java.nio.file.Files.newOutputStream(Files.java:228)
	at java.base/java.nio.file.Files.copy(Files.java:3160)
	at com.io7m.xstructural.vanilla.internal.XSEPUBCreator.writeContainerFile(XSEPUBCreator.java:491)
	at com.io7m.xstructural.vanilla.internal.XSEPUBCreator.execute(XSEPUBCreator.java:254)