title: Dependency issue trying to install php-mbstring on ec2
body: <p>I am trying to install <code>yii2</code> on my Amazon Linux AMI instance, it requires the <code>php-mbstring</code> extension to work.  </p>
  
  <p>When I tried to run <code>sudo yum install php-mbstring</code> it returned this error:</p>
  
  <blockquote>
    <p>Error: php56-common conflicts with php-common-5.3.29-1.8.amzn1.x86_64</p>
  </blockquote>
  
  <pre><code>Loaded plugins: priorities, update-motd, upgrade-helper
  amzn-main/latest                                         | 2.1 kB     00:00
  amzn-updates/latest                                      | 2.3 kB     00:00
  2494 packages excluded due to repository priority protections
  Resolving Dependencies
  --&gt; Running transaction check
  ---&gt; Package php-mbstring.x86_64 0:5.3.29-1.8.amzn1 will be installed
  --&gt; Processing Dependency: php-common(x86-64) = 5.3.29-1.8.amzn1 for package: php-mbstring-5.3.29-1.8.amzn1.x86_64
  --&gt; Running transaction check
  ---&gt; Package php-common.x86_64 0:5.3.29-1.8.amzn1 will be installed
  --&gt; Processing Conflict: php56-common-5.6.9-1.112.amzn1.x86_64 conflicts php-common &lt; 5.5.22-1.98
  --&gt; Finished Dependency Resolution
  Error: php56-common conflicts with php-common-5.3.29-1.8.amzn1.x86_64
  You could try using --skip-broken to work around the problem
  You could try running: rpm -Va --nofiles --nodigest
  </code></pre>
  
  <p>Thanks for your time in advance</p>