Fixed build on Mac OS

[tcptps]

ATTENTION fixed gcc Version: 10

.gitignore: added .DS_Store to make developing on a Mac easier .travis/install.sh: added gcc@10 to fullfill the gcc on version 10 requirement CMakeLists.txt added differentiation for MacOS where it only includes the headers which are shipped with the repo build.sh added differentiation for MacOS to use gcc Version 10 installed via brew, use sepcial Arguments, include the headers which are shipped with the repo