title: I cannot find signingConfigs DSL container in android studio
body: <p>I wanted to check my application on emulator but unfortunately logcat showed me an error:" <em>Installation failed since the APK was either not signed, or signed incorrectly.
  If this is a Gradle-based project, then make sure the signing configuration is specified in the Gradle build script</em>.".After that i'm tried to find a solution to this problem and i found  an answer on stackoverflow,however,there are no explanation on where signingConfigs DSL container is.It may seem ridiculous but i'm neophyte on android programming.Please help me!!!
  P.S. I'm using Android Studio</p>