fix: http protocol use sshurl by default

PR-URL: #48
Credit: @fengmk2
Close: #48
Reviewed-by: @isaacs

git-host.js

@@ -151,6 +151,6 @@ GitHost.prototype.getDefaultRepresentation = function () {
 }
 
 GitHost.prototype.toString = function (opts) {
-  const method = this.default || /* istanbul ignore next */ 'sshurl'
-  return this[method](opts)
+  if (this.default && typeof this[this.default] === 'function') return this[this.default](opts)
+  return this.sshurl(opts)
 }

test/basic.js

@@ -35,5 +35,7 @@ test('basic', function (t) {
   t.is(HostedGit.fromUrl('git+file:///foo/bar'), undefined, 'url that has no host')
   t.is(HostedGit.fromUrl('github.com/abc/def/'), undefined, 'forgot the protocol')
   t.is(HostedGit.fromUrl('completely-invalid'), undefined, 'not a url is not hosted')
+
+  t.is(HostedGit.fromUrl('http://github.com/foo/bar').toString(), 'git+ssh://git@github.com/foo/bar.git', 'github http protocol use git+ssh urls')
   t.end()
 })