v1.3.1

Python coding:

• Standardize Imports - Part I, #176 #206
• split functions from nlbin #244

Other features:

• Clip exponential in ffunc to avoid overflow #201
• Ignored empty lines in fonts list file #233
• Change checks for write_page_segmentation #220 (allow also small images for segmentation)
• Expand tests for coverage and CI

Bugfixing: #251, #252