title: OpenSSL not found on MacOS Sierra
body: <p>I am trying to install a PHP MongoDB driver but the installation is failing because it cannot locate the OpenSSL.</p>
  
  <pre><code>/Users/username/mongo-php-driver/src/libmongoc/src/mongoc/mongoc-crypto-openssl.c:24:10: fatal error: 'openssl/sha.h' file not found
  #include &lt;openssl/sha.h&gt;
           ^
  1 error generated.
  make: *** [src/libmongoc/src/mongoc/mongoc-crypto-openssl.lo] Error 1
  </code></pre>
  
  <p>I read that this has something to do with the latest version of MacOS? Is there a way to do it, as I really need to install this driver.</p>