Add proxy support to ca_cert::ca (remote_file)

[pelacables]

In our case we need to use the proxy while downloading the certificates. remote_file fails gives tiemouts.

I implemented an ugly patch so we can pass "proxy" when using ca_cert::ca, but I guess that you would like to implemnt it in a way it supports the same proxy-related parameters than remote_file.

The remote_file type provides several proxy-related parameters. You should choose between specifying proxy or specifying proxy_host and proxy_port. The following two examples are equivalent.

I can create a PR in case you don't want to implement more than the plain "proxy" way of defining a proxy in remote_file.

[pelacables]

Sorry, just in case you are interested in the "patch" (Puppet 5):

# diff modules/ca_cert/manifests/ca.pp modules/ca_cert.ori/manifests/ca.pp
43d42
<   Optional[String] $proxy        = undef,
111,115d109
<           }
<           if $proxy != undef {
<             Remote_file["$ca_cert"] {
<               proxy => $proxy,
<             }