WIP epd bringup

[sergei]

• epd_7in5bc_test.py - wrong dimensions
• epd_7in5_test.py - wrong dimensions
• epd_7in5b_HD_test.py - wrong dimensions
• epd_7in5_HD_test.py - no response
• epd_7in5_V2_test.py - bad contrast
• epd_7in5b_V2_test.py seems to behave OK but alot of flickering while waiting fro new image

[sergei]

The flickering seems to be normal https://github.com/waveshare/e-Paper/issues/31