Update gentoo dockerfile

Install kpatch without modules
Use override on portage settings instead of append
Use testing kpatch and unstable pesign

Author: aliceinwire

gentoo.Dockerfile

@@ -10,7 +10,8 @@ COPY --from=portage /usr/portage /usr/portage
 MAINTAINER alicef@gentoo.org
 
 RUN mkdir /etc/portage/package.keywords
-RUN echo "dev-lang/python sqlite" >> /etc/portage/package.use/python
-RUN echo "sys-apps/elivepatch-server ~amd64" >> /etc/portage/package.keywords/elivepatch
+RUN echo "dev-lang/python sqlite" > /etc/portage/package.use/python
+RUN echo "sys-apps/elivepatch-server ~amd64\nsys-kernel/kpatch **\napp-crypt/pesign ~amd64" > /etc/portage/package.keywords/elivepatch
 
 RUN ROOT=/destination emerge -qv sys-apps/elivepatch-server
+RUN ROOT=/destination USE="-modules" emerge -qv sys-kernel/kpatch