implement the `clean` command.
implement the `clean` command.

superalex/buildozer,rnixx/buildozer,inclement/buildozer,inclement/buildozer,kivy/buildozer,techtonik/buildozer,rnixx/buildozer,bob-the-hamster/buildozer,kived/buildozer,kivy/buildozer,rnixx/buildozer,techtonik/buildozer,inclement/buildozer,inclement/buildozer,cbenhagen/buildozer,dvenkatsagar/buildozer,kived/buildozer,kivy/buildozer,rnixx/buildozer,kivy/buildozer