title: mongodb php extension install giving configuration error
body: <p>So I am trying to install the mongodb pecl extension using <code>sudo pecl install mongodb</code> and get the following:</p>
  
  <pre><code>downloading mongodb-1.1.2.tgz ...
  Starting to download mongodb-1.1.2.tgz (642,582 bytes)
  ....done: 642,582 bytes
  349 source files, building
  running: phpize
  Configuring for:
  PHP Api Version:         20151012
  Zend Module Api No:      20151012
  Zend Extension Api No:   320151012
  building in /var/tmp/pear-build-rootGfSZhI/mongodb-1.1.2
  running: /var/tmp/mongodb/configure --with-php-config=/usr/bin/php-config
  checking for grep that handles long lines and -e... /bin/grep
  checking for egrep... /bin/grep -E
  checking for a sed that does not truncate output... /bin/sed
  checking for cc... cc
  checking for C compiler default output file name... a.out
  checking whether the C compiler works... yes
  checking whether we are cross compiling... no
  checking for suffix of executables...
  checking for suffix of object files... o
  checking whether we are using the GNU C compiler... yes
  checking whether cc accepts -g... yes
  checking for cc option to accept ISO C89... none needed
  checking how to run the C preprocessor... cc -E
  checking for icc... no
  checking for suncc... no
  checking whether cc understands -c and -o together... yes
  checking for system library directory... lib
  checking if compiler supports -R... no
  checking if compiler supports -Wl,-rpath,... yes
  checking build system type... x86_64-unknown-linux-gnu
  checking host system type... x86_64-unknown-linux-gnu
  checking target system type... x86_64-unknown-linux-gnu
  checking for PHP prefix... /usr
  checking for PHP includes... -I/usr/include/php -I/usr/include/php/main -I/usr/include/php/TSRM -I/usr/include/php/Zend -I/usr/include/php/ext -I/usr/include/php/ext/date/lib
  checking for PHP extension directory... /usr/lib64/php/modules
  checking for PHP installed headers prefix... /usr/include/php
  checking if debug is enabled... no
  checking if zts is enabled... no
  checking for re2c... re2c
  checking for re2c version... 0.13.5 (ok)
  checking for gawk... gawk
  checking whether to enable mongodb support... yes, shared
  checking OpenSSL dir for mongodb... yes
  checking PHP version... 70000
  checking whether to enable developer build flags... no
  checking whether to enable code coverage... no
  checking whether to use system libbson... no
  checking configuring libmongoc... ...
  checking whether to use system libmongoc... no
  checking for pkg-config... /usr/bin/pkg-config
  configure: error: Cannot find OpenSSL's &lt;evp.h&gt;
  ERROR: `/var/tmp/mongodb/configure --with-php-config=/usr/bin/php-config' failed
  </code></pre>
  
  <p>Any ideas why this isn't working?</p>