Android - Assertj Android - Run error

I´m trying to run assertj-android but it send an error. (it runs fine with junit 4)

My Dependencies:

dependencies {
    testCompile 'junit:junit:4.12'
    androidTestCompile ('com.squareup.assertj:assertj-android:1.0.0'){
        exclude group:'com.android.support', module:'support-annotations'
    }
}

My Build type:

buildTypes {
    debug {
        signingConfig signingConfigs.debug

        minifyEnabled true
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }

My progard-rules.pro:

## Assertj
-dontwarn org.assertj.**
-keep class org.assertj.** {*;}

And I get this error on run:

:app:proguardDebugAndroidTest
Warning:org.assertj.core.api.JUnitSoftAssertions: can't find superclass or interface org.junit.rules.TestRule
Warning:org.assertj.core.api.JUnitSoftAssertions$1: can't find superclass or interface org.junit.runners.model.Statement
Warning:org.assertj.core.api.JUnitSoftAssertions: can't find referenced class org.junit.rules.TestRule
Warning:org.assertj.core.api.JUnitSoftAssertions: can't find referenced class org.junit.runners.model.Statement
Warning:org.assertj.core.api.JUnitSoftAssertions: can't find referenced class org.junit.runner.Description
Warning:org.assertj.core.api.JUnitSoftAssertions: can't find referenced class org.junit.runners.model.Statement
Warning:org.assertj.core.api.JUnitSoftAssertions: can't find referenced class org.junit.runner.Description
Warning:org.assertj.core.api.JUnitSoftAssertions$1: can't find referenced class org.junit.runners.model.Statement
Warning:org.assertj.core.api.JUnitSoftAssertions$1: can't find referenced class org.junit.runners.model.MultipleFailureException
Warning:org.assertj.core.api.JUnitSoftAssertions$1: can't find referenced class org.junit.runners.model.Statement
Warning:org.assertj.core.internal.JavaBeanDescriptor: can't find referenced class java.beans.PropertyDescriptor
Warning:org.assertj.core.internal.PropertySupport: can't find referenced class java.beans.PropertyDescriptor
Warning:org.assertj.core.internal.cglib.core.DebuggingClassWriter$1: can't find referenced class org.assertj.core.internal.cglib.asm.util.TraceClassVisitor
Warning:org.assertj.core.internal.cglib.core.ReflectUtils: can't find referenced class java.beans.PropertyDescriptor
Warning:org.assertj.core.internal.cglib.core.ReflectUtils: can't find referenced class java.beans.IntrospectionException
Warning:org.assertj.core.internal.cglib.core.ReflectUtils: can't find referenced class java.beans.Introspector
Warning:org.assertj.core.internal.cglib.core.ReflectUtils: can't find referenced class java.beans.BeanInfo
Warning:org.assertj.core.internal.cglib.core.ReflectUtils: can't find referenced class java.beans.PropertyDescriptor
Warning:org.assertj.core.internal.cglib.core.ReflectUtils: can't find referenced class java.beans.BeanInfo
Warning:org.assertj.core.internal.cglib.core.ReflectUtils: can't find referenced class java.beans.PropertyDescriptor
Warning:org.assertj.core.internal.cglib.core.ReflectUtils: can't find referenced class java.beans.IntrospectionException
Warning:org.assertj.core.util.introspection.Introspection: can't find referenced class java.beans.Introspector
Warning:org.assertj.core.util.introspection.Introspection: can't find referenced class java.beans.BeanInfo
Warning:org.assertj.core.util.introspection.Introspection: can't find referenced class java.beans.PropertyDescriptor
Warning:org.assertj.core.util.introspection.Introspection: can't find referenced class java.beans.BeanInfo
Warning:org.assertj.core.util.xml.XmlStringPrettyFormatter: can't find referenced class org.w3c.dom.bootstrap.DOMImplementationRegistry
Warning:there were 59 unresolved references to classes or interfaces.
         You may need to add missing library jars or update their versions.
         If your code works fine without the missing classes, you can suppress
         the warnings with '-dontwarn' options.
         (http://ift.tt/1a4OICW)
:app:proguardDebugAndroidTest FAILED
:app:newRelicDeinstrumentTask
[newrelic.info] Deinstrumenting...
Error:Execution failed for task ':app:proguardDebugAndroidTest'.
> java.io.IOException: Please correct the above warnings first.

Why?