fix(router): account for dashes in custom domains

confd turns hyphens to dashes, so we need to account for that in
domains. Since confd does not have native support for strings.Replace,
I've had to fork our current branch and backport strings.Replace as a
template function.

Author: Matthew Fisher

router/image/Dockerfile

@@ -5,8 +5,8 @@ ENV DEBIAN_FRONTEND noninteractive
 # install common packages
 RUN apt-get update && apt-get install -y curl net-tools sudo
 
-# install confd
-RUN curl -sSL -o /usr/local/bin/confd https://s3-us-west-2.amazonaws.com/opdemand/confd-git-b8e693c \
+# install confd from https://github.com/deis/confd/tree/deis
+RUN curl -sSL -o /usr/local/bin/confd https://s3-us-west-2.amazonaws.com/opdemand/confd-git-4c50136 \
     && chmod +x /usr/local/bin/confd
 
 # install common packages

router/image/templates/nginx.conf

@@ -157,9 +157,11 @@ http {
     server {
         server_name {{ Base $domain.Key }};
         {{/* if a SSL certificate is installed for this domain, use SSL */}}
-        {{/* Note (bacongobbler): domains are separate from the default platform domain, */}}
+        {{/* NOTE (bacongobbler): domains are separate from the default platform domain, */}}
         {{/* so we can't rely on deis.conf as each domain is an island */}}
-        {{ if index $root (printf "deis_certs_%s_cert" (Base $domain.Key)) }}
+        {{/* FIXME (bacongobbler): confd turns hyphens to dashes, so we need to account */}}
+        {{/* for that in domains */}}
+        {{ if index $root (printf "deis_certs_%s_cert" (Replace (Base $domain.Key) "-" "_" -1)) }}
         server_name_in_redirect off;
         port_in_redirect off;
         listen 80;