fedora 20 is EOL remove from rpm builder

Signed-off-by: Jessica Frazelle <acidburn@docker.com>

contrib/builder/rpm/fedora-20/Dockerfile

@@ -1,15 +0,0 @@
-#
-# THIS FILE IS AUTOGENERATED; SEE "contrib/builder/rpm/generate.sh"!
-#
-
-FROM fedora:20
-
-RUN yum install -y @development-tools fedora-packager
-RUN yum install -y btrfs-progs-devel device-mapper-devel glibc-static libselinux-devel sqlite-devel tar
-
-ENV GO_VERSION 1.4.2
-RUN curl -fSL "https://storage.googleapis.com/golang/go${GO_VERSION}.linux-amd64.tar.gz" | tar xzC /usr/local
-ENV PATH $PATH:/usr/local/go/bin
-
-ENV AUTO_GOPATH 1
-ENV DOCKER_BUILDTAGS selinux

docs/installation/fedora.md

@@ -12,7 +12,6 @@ parent = "smn_linux"
 
 Docker is supported on the following versions of Fedora:
 
-- Fedora 20 
 - Fedora 21
 - Fedora 22