removed cflag -Werror
removed cflag -Werror

This solves #128

gcc7 has a compatibility problem with python and issues a warning as described at https://bugzilla.redhat.com/show_bug.cgi?id=1473425  

Setting the `-Werror` flag treats all warnings as errors, which fails the build.  IMHO it is better to remove the flag from regular builds.  Advanced users can add it if they choose to.
coreemu/core,coreemu/core,coreemu/core,coreemu/core