Remove glog dependency from assertion macro

Removes glog dependency.

Related to https://github.com/jubatus/jubatus/issues/746 and https://github.com/jubatus/jubatus/pull/821
How about using `std::terminate` to be consistent with https://github.com/jubatus/jubatus_core/blob/c5e130aa98e6f3076e6c1dc4ae134a73bc014f6d/jubatus/core/common/assert.hpp#L75 ?