Unable to merge Dex error: Android Studio 3.0

I've tried again and again to fix this problem, but none of the solutions proposed in the other questions worked for me. After merging my code with my teammates' code, I haven't been able to run my app due to this bug. I've cleaned and rebuilt my project multiple times, but the error still keeps coming up:

Error:Execution failed for task ':app:transformDexArchiveWithExternalLibsDexMergerForDebug'. java.lang.RuntimeException: java.lang.RuntimeException: com.android.builder.dexing.DexArchiveMergerException: Unable to merge dex

I've tried fixing gradle warnings, updating gradle compile library statements, and putting this flag in my default config:

multiDexEnabled true

The only fix that produced something different was the above flag, which allowed me to actually run the app, but then a different run-time error occurs:

E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.aaronliang.flow_v1, PID: 11780 java.lang.RuntimeException: Unable to get provider >com.google.firebase.provider.FirebaseInitProvider: >java.lang.ClassNotFoundException: Didn't find class >"com.google.firebase.provider.FirebaseInitProvider" on path: DexPathList[[zip >file "/data/app/com.example.aaronliang.flow_v1->177.apk"],nativeLibraryDirectories=[/data/app->lib/com.example.aaronliang.flow_v1-177, /vendor/lib, /system/lib]]

Here are my current gradle build files:

Project build:

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        jcenter()
        mavenCentral()
    }
    dependencies {

        classpath 'com.android.tools.build:gradle:3.0.0'
        classpath 'com.google.gms:google-services:3.1.0'

        //classpath 'com.android.tools.build:gradle:2.3.3'
        //classpath 'com.google.gms:google-services:3.1.0'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        jcenter()
        maven { url "https://jitpack.io" }
        maven { url "https://maven.google.com" }
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

App build:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 26
    buildToolsVersion '26.0.2'
    defaultConfig {
        multiDexEnabled true
        applicationId "com.example.aaronliang.flow_v1"
        minSdkVersion 15
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:26.1.0'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    compile 'com.android.volley:volley:1.0.0'
    compile 'com.github.bumptech.glide:glide:3.7.0'
    compile 'com.google.firebase:firebase-firestore:11.6.0'
    compile 'com.google.firebase:firebase-auth:11.6.0'
    compile 'com.google.firebase:firebase-core:11.6.0'
    compile 'com.google.android.gms:play-services:11.6.0'
    compile 'com.github.woxthebox:draglistview:1.5.0'
    //compile 'com.github.PhilJay:MPAndroidChart:v3.0.2'
    compile 'com.jjoe64:graphview:4.2.1'
    testCompile 'junit:junit:4.12'
}
apply plugin: 'com.google.gms.google-services'

configurations.all {
    resolutionStrategy.eachDependency { DependencyResolveDetails details ->
        def requested = details.requested
        if (requested.group == 'com.android.support') {
            if (!requested.name.startsWith("multidex")) {
                details.useVersion '25.3.1'
            }
        }

    }
}

Any help would be appreciated, because this project's due soon!