Remove executable bit from plain text files

[Daniel15]

Removes the executable bit (chmod a-x) from the license and readme, as it doesn't make sense for plain text files to be marked as executable.

Right now, this causes lint warnings when building a Debian package for a project that pulls in object-path as a dependency, as it thinks the file is an executable:

W: yarn: non-standard-executable-perm usr/share/yarn/node_modules/object-path/LICENSE 0744 != 0755

[coveralls]

Coverage remained the same at 99.424% when pulling 60e8661 on Daniel15:noexec into f01ab7c on mariocasciaro:master.

[mariocasciaro]

Makes sense, thanks!