Could not find Constraint Layout inside Android Studio
<p>Everything was working fine inside studio, but then I get error:</p>

<pre><code>Could not find com.android.support.constraint:constraint-layout:1.0.0-beta4.
</code></pre>

<p>Problem is that I can not install Constraint layout in Android Studio because I am using Ubuntu.I can not find SDK Tools(System Settings) to install manually like usually on MAC.</p>

<p>None of solutions here worked for me because they are mostly for MAC OS.</p>

<p>I am using Android 2.2 on Ubuntu 14.04, and Gradle 2.2.2.</p>