Bump OCCT version number in README.md to 6.7.1
Bump OCCT version number in README.md to 6.7.1

tpaviot/oce,Tridify/oce,finetjul/oce,tpaviot/oce,EvgeneOskin/oce,finetjul/oce,finetjul/oce,heartvalve/oce,heartvalve/oce,heartvalve/oce,tpaviot/oce,Tridify/oce,EvgeneOskin/oce,Tech-XCorp/oce,Tech-XCorp/oce,finetjul/oce,mathstuf/oce,BenoitPerrot/oce,Tridify/oce,BenoitPerrot/oce,Tech-XCorp/oce,BenoitPerrot/oce,heartvalve/oce,EvgeneOskin/oce,Tridify/oce,EvgeneOskin/oce,tpaviot/oce,mathstuf/oce,Tech-XCorp/oce,tpaviot/oce,Tridify/oce,mathstuf/oce,Tech-XCorp/oce,BenoitPerrot/oce,EvgeneOskin/oce,BenoitPerrot/oce,finetjul/oce,heartvalve/oce,mathstuf/oce,mathstuf/oce