v0.5.0

• Feature / BC break: Support Connector without DNS
  (#46 by @clue)

  BC break: The Connector class now serves as a BC layer only.
  The TcpConnector and DnsConnector classes replace its functionality.
  If you're merely using this class, then you're recommended to upgrade as
  per the below snippet – existing code will still work unchanged.
  If you're extending the Connector (generally not recommended), then you
  may have to rework your class hierarchy.

  // old (still supported, but marked deprecated)
  $connector = new Connector($loop, $resolver);
  
  // new equivalent
  $connector = new DnsConnector(new TcpConnector($loop), $resolver);
  
  // new feature: supports connecting to IP addresses only
  $connector = new TcpConnector($loop);

• Feature: Add socket and SSL/TLS context options to connectors
  (#52 by @clue)

• Fix: PHP 5.6+ uses new SSL/TLS context options
  (#61 by @clue)

• Fix: Move SSL/TLS context options to SecureConnector
  (#43 by @clue)

• Fix: Fix error reporting for invalid addresses
  (#47 by @clue)

• Fix: Close stream resource if connection fails
  (#48 by @clue)

• First class support for PHP 5.3 through PHP 7 and HHVM
  (#53, #54 by @clue)

• Add integration tests for SSL/TLS sockets
  (#62 by @clue)