Android Studio dexDebug problems

Question

So I have this project which uses some libraries on Github. When I try to compile it the process always stops at dexDebug with something like

UNEXPECTED TOP-LEVEL EXCEPTION:
java.lang.IllegalArgumentException: already added: Landroid/support/v4/widget/SearchViewCompatIcs$MySearchView;
at com.android.dx.dex.file.ClassDefsSection.add(ClassDefsSection.java:122)
at com.android.dx.dex.file.DexFile.add(DexFile.java:161)
at com.android.dx.command.dexer.Main.processClass(Main.java:732)
at com.android.dx.command.dexer.Main.processFileBytes(Main.java:673)
at com.android.dx.command.dexer.Main.access$300(Main.java:83)
at com.android.dx.command.dexer.Main$1.processFileBytes(Main.java:602)
at com.android.dx.cf.direct.ClassPathOpener.processArchive(ClassPathOpener.java:284)
at com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:166)
at com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:144)
at com.android.dx.command.dexer.Main.processOne(Main.java:632)
at com.android.dx.command.dexer.Main.processAllFiles(Main.java:510)
at com.android.dx.command.dexer.Main.runMonoDex(Main.java:280)
at com.android.dx.command.dexer.Main.run(Main.java:246)
at com.android.dx.command.dexer.Main.main(Main.java:215)
at com.android.dx.command.Main.main(Main.java:106)

UNEXPECTED TOP-LEVEL EXCEPTION:
java.lang.IllegalArgumentException: already added: Landroid/support/v4/util/LruCache;
at com.android.dx.dex.file.ClassDefsSection.add(ClassDefsSection.java:122)
at com.android.dx.dex.file.DexFile.add(DexFile.java:161)
at com.android.dx.command.dexer.Main.processClass(Main.java:732)
at com.android.dx.command.dexer.Main.processFileBytes(Main.java:673)
at com.android.dx.command.dexer.Main.access$300(Main.java:83)
at com.android.dx.command.dexer.Main$1.processFileBytes(Main.java:602)
at com.android.dx.cf.direct.ClassPathOpener.processArchive(ClassPathOpener.java:284)
at com.android.dx.cf.direct.ClassPathOpener.processOne(ClassPathOpener.java:166)
at com.android.dx.cf.direct.ClassPathOpener.process(ClassPathOpener.java:144)
at com.android.dx.command.dexer.Main.processOne(Main.java:632)
at com.android.dx.command.dexer.Main.processAllFiles(Main.java:510)
at com.android.dx.command.dexer.Main.runMonoDex(Main.java:280)
at com.android.dx.command.dexer.Main.run(Main.java:246)
at com.android.dx.command.dexer.Main.main(Main.java:215)
at com.android.dx.command.Main.main(Main.java:106)
2 errors; aborting

I'm very confusing as I am new to Android Studio. I tried excluding module 'support-v4' from all the libraries but it is still the same error. Since the libraries are added as dependencies I don't know which libraries they use in Project structure and through gradlew -q dependencies (it says something like "no configuration"). There's no jar file in folder libs either.

My app build.gradle

dependencies {
compile fileTree(include: '*.jar', dir: 'libs')
compile 'com.android.support:appcompat-v7:22.0.0'
compile ('com.melnykov:floatingactionbutton:1.2.0')
compile('me.drakeet.materialdialog:library:1.2.2')
compile (project(':library'))
}

android {
compileSdkVersion 21
buildToolsVersion "21.1.2"

dexOptions {
    preDexLibraries = false
}

sourceSets {
    main {
        manifest.srcFile 'AndroidManifest.xml'
        java.srcDirs = ['src']
        resources.srcDirs = ['src']
        aidl.srcDirs = ['src']
        renderscript.srcDirs = ['src']
        res.srcDirs = ['res']
        assets.srcDirs = ['assets']
    }

    // Move the tests to tests/java, tests/res, etc...
    instrumentTest.setRoot('tests')

    // Move the build types to build-types/<type>
    // For instance, build-types/debug/java, build-types/debug/AndroidManifest.xml, ...
    // This moves them out of them default location under src/<type>/... which would
    // conflict with src/ being used by the main source set.
    // Adding new build types or product flavors should be accompanied
    // by a similar customization.
    debug.setRoot('build-types/debug')
    release.setRoot('build-types/release')
}
}

library build.gradle (I imported the project into Android Studio). It requires support v4

buildscript {
repositories {
    jcenter()
}
dependencies {
    classpath 'com.android.tools.build:gradle:1.0.0'
    classpath 'com.github.dcendents:android-maven-plugin:1.2'
}
}

   repositories {
   jcenter()
}

apply plugin: 'com.android.library'
apply plugin: 'android-maven'

dependencies {
compile 'com.android.support:support-v4:22.0.0'
}

android {
compileSdkVersion 21
buildToolsVersion "21.1.2"

defaultConfig {
    minSdkVersion 8
    targetSdkVersion 21
    versionCode 1
    versionName "1.0"
}
buildTypes {
sourceSets {
    main {
        manifest.srcFile 'AndroidManifest.xml'
            java.srcDirs = ['src']
            resources.srcDirs = ['src']
            aidl.srcDirs = ['src']
            renderscript.srcDirs = ['src']
    res.srcDirs = ['res']
    }
}
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}
}

Any help is appreciated, it is getting frustrating for me.