Firefox Pre AMO Grunt

exec: {
    firefox_clean: 'call _src/chrome/ffclean.bat',
},
webext_builder: {
    firefox_sign: {
        targets: ['firefox-xpi'],
        "jwtIssuer": process.env.psdleSignIssuer,
        "jwtSecret": process.env.psdleSignSecret,
        files: {
            ".": ["_src/chrome/psdle/"]
        }
    }
}
grunt.loadNpmTasks('grunt-webext-builder');`
grunt.registerTask('firefox', 'Create and sign Firefox extension.', function() {
    grunt.task.run([
        'webext_builder:firefox_sign',
        'exec:firefox_clean'
    ]);
});

::psdle/_src/chrome/ffclean.bat
del psdle-*-raw.xpi
move /Y psdle-*.xpi psdle.xpi