With the official release of Android Studio, Eclipse with ADT seems no more supported.
If you have been using Eclipse with ADT, be aware that Android Studio is now the official IDE for Android, so you should migrate to Android Studio in order to continue to receive all the latest IDE updates. For help moving projects, see Migrating to Android Studio.
After installing the new release, you may read Migrating Gradle Projects to version 1.0.0 in particular for the error
method not found: 'runProguard()'
that has to be replaced with
minifyEnabled in your build.gradle files.