I didn't find dexguard-license.txt file in dexguard.please help me in gradle setup in android studio 
here is my gradle console output

```
Executing tasks: [:app:assembleDebug]
.....
Can't find a DexGuard license file.
You should place your license file dexguard-license.txt
1) in a location defined by the Java system property 'dexguard.license',
2) in a location defined by the OS environment variable 'DEXGUARD_LICENSE',
3) in your home directory, 
4) in the class path, or
5) in the same directory as the DexGuard jar.

```