TLS issue with Mono on Ubuntu 15.x
As far as I am aware mono that ships with Ubuntu machines do not have support for TLS 1.1 or 1.2.  So the build fails on any distro that doesnt have a mono with TLS 1.1 or 1.2 support (which I dont think any version of mono has yet).  Therefore we need checks to see if TLS 1.1 or 1.2 support exists or it will fail here in: Fleck/WebSocketServer.cs around line 130ish

//Change the below
 EnabledSslProtocols = SslProtocols.Tls12 | SslProtocols.Tls11 | SslProtocols.Tls; 
to
EnabledSslProtocols = SslProtocols.Tls; // changed by wmp

I dont know who wmp is,  but it appears they likely ran into the same problem but then it was reverted for unknown reasons (likely during build on a windows system maybe where C# would have support for TLS?

Anyway,  a better way to handle this would be to check to see if Tls11 and 12 are even supported or not by checking to see which mono version is doing the build or perhaps just a check to see if it's MSVC doing the build or Mono and then once Mono has support,  change that check to see which version of Mono is doing the build.

This is the error you get if you attempt to build this project with Mono as instructed in the Readme:
/root/Documents/xmr/webminerpool/server/Server/Server.csproj (default targets) ->
/usr/lib/mono/4.5/Microsoft.CSharp.targets (CoreCompile target) ->

        Fleck/WebSocketServer.cs(133,42): error CS0117: `System.Security.Authentication.SslProtocols' does not contain a definition for `Tls12'

         0 Warning(s)
         1 Error(s)

Time Elapsed 00:00:00.7800490
