Added Remote Access VPN functionality

[swill]

I have added remote access vpn functionality to the terraform provider.

This extension of the plugin functionality requires the following PR against thego-cloudca library to be merged: https://github.com/cloud-ca/go-cloudca/pull/21

In order to test, I was using a locally built version of the go-cloudca library, so the following modification is likely to change once the PR is merged.

diff --git a/vendor/modules.txt b/vendor/modules.txt
index 3472e11..7f08477 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -46,7 +46,7 @@ github.com/bgentry/go-netrc/netrc
 github.com/bgentry/speakeasy
 # github.com/blang/semver v3.5.1+incompatible
 github.com/blang/semver
-# github.com/cloud-ca/go-cloudca v1.3.0
+# github.com/cloud-ca/go-cloudca v1.3.1-0.20190304205722-70b4395e647b
 github.com/cloud-ca/go-cloudca
 github.com/cloud-ca/go-cloudca/api
 github.com/cloud-ca/go-cloudca/configuration

I have implemented this functionality in a terraform script locally to validate it functions as expected.

[khos2ow]

@swill lint job has failed, can you run make tools lint locally and fix the issues and update the PR please?

[swill]

Done...

[pdube]

🚀