Enabled PDFDevice in the with statement

[massongit]

I enabled pdfminer.pdfdevice.PDFDevice and it's inherited classes in the with statement.

Example (Use pdfminer.converter.TextConverter which is pdfminer.pdfdevice.PDFDevice's inherited classes):

import io

import pdfminer.converter
import pdfminer.layout
import pdfminer.pdfinterp
import pdfminer.pdfpage


def main():
    with io.StringIO() as return_text:
        resource_manager = pdfminer.pdfinterp.PDFResourceManager()

        with pdfminer.converter.TextConverter(resource_manager, return_text, laparams=pdfminer.layout.LAParams(detect_vertical=True)) as device:
            ...


if __name__ == '__main__':
    main()