title: Erlang Cowboy - Dependency crypto is specified as a dependency but is not reachable by the system
body: <p>I have installed Erlang vesion 19.3 on CentOS 7 linux server. Yesterday, I downloaded Cowboy HTTP server (latest version). In the examples/hello_world directory I have run <code>make</code> (version 4.1) command and got the following error</p>
  
  <p><code>Dependency crypto is specified as a dependency but is not reachable by the system.</code></p>
  
  <p>Can anyone help me to resolve the problem?</p>