For some reason when I add compile 'com.firebaseui:firebase-ui-storage:0.6.0' to the dependencies it creates a conflict in the gradle with 
implementation 'com.android.support:appcompat-v7:27.0.2'
Here is a full copy of my Gradle:-
apply plugin: 'com.android.application'
android {
    compileSdkVersion 27
    defaultConfig {
        applicationId "com.example.nick.listofrestaurants"
        minSdkVersion 15
        targetSdkVersion 27
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}
//repositories {
//    mavenCentral()
//    google()
//}
dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:27.0.2' //issue here
    implementation 'com.android.support.constraint:constraint-layout:1.0.2'
    implementation 'com.google.firebase:firebase-storage:11.8.0'
    implementation 'com.google.firebase:firebase-auth:11.8.0'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.1'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
    implementation 'com.android.support:cardview-v7:27.0.2'
    compile 'com.google.android.gms:play-services-maps:11.8.0'
    compile 'com.google.android.gms:play-services-location:11.8.0'
    compile 'com.android.support:design:27.0.2'
    compile 'com.firebase:firebase-client-android:2.5.0'
    compile 'com.firebaseui:firebase-ui-storage:0.6.0'
    //implementation 'com.github.bumptech.glide:glide:3.8.0'
    //annotationProcessor 'com.github.bumptech.glide:compiler:3.8.0'
}
apply plugin: 'com.google.gms.google-services'`

 
     
    