Create a initial buildozer.spec in the current directory

def cmd_init(self, *args):
        '''Create a initial buildozer.spec in the current directory
        '''
        if exists('buildozer.spec'):
            print('ERROR: You already have a buildozer.spec file.')
            exit(1)
        copyfile(join(dirname(__file__), 'default.spec'), 'buildozer.spec')
        print('File buildozer.spec created, ready to customize!')