v1.7.0

Fixed:

• Makefile/tests: fix tests, update to resmgr cwd semantics, add dewarp
• layout-analysis: use correct pageId
• tiseg/layout-analysis: use TF SavedFormat instead of HDF5
• dewarp/layout-analysis: load during init (setup instead of process)
• dewarp: fix image input (in-memory instead of file-based)
• dewarp: fix image output (resizing with better quality)
• dewarp: fix/update pix2pixHD for CPU-only and newer PyTorch
• dewarp: rename parameters (now resize_{mode,width,height})
• dewarp: fix oplevel region, update to ocrd_mets changes
• update requirements
• improve README