не удалось разрешить все зависимости в студии Android после обновления до 3.0.1

Я получаю следующие ошибки:

Error:Unable to resolve dependency for ':app@debug/compileClasspath': Could not resolve com.android.support:appcompat-v7:26.1.0.

Error:Unable to resolve dependency for ':app@debugAndroidTest/compileClasspath': Could not resolve com.android.support.test:runner:1.0.1.

Error:Unable to resolve dependency for ':app@debugAndroidTest/compileClasspath': Could not resolve com.android.support.test.espresso:espresso-core:3.0.1.

Error:Unable to resolve dependency for ':app@debugAndroidTest/compileClasspath': Could not resolve com.android.support.test.espresso:espresso-core:3.0.1.

Error:Unable to resolve dependency for ':app@debugUnitTest/compileClasspath': Could not resolve com.android.support:appcompat-v7:26.1.0.

Error:Unable to resolve dependency for ':app@debugUnitTest/compileClasspath': Could not resolve junit:junit:4.12.

Error:Unable to resolve dependency for ':app@release/compileClasspath': Could not resolve com.android.support:appcompat-v7:26.1.0.

Error:Unable to resolve dependency for ':app@release/compileClasspath': Could not resolve com.android.support:appcompat-v7:26.1.0.

Error:Unable to resolve dependency for ':app@releaseUnitTest/compileClasspath': Could not resolve junit:junit:4.12.

Файл приложения build.gradle (проект: MyApplication)

buildscript {

repositories {
    google()
    jcenter()
}
dependencies {
    classpath 'com.android.tools.build:gradle:3.0.1'


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

allprojects {
repositories {
    google()
    jcenter()
}
}

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

Файл приложения build.gradle (Module:app)

apply plugin: 'com.android.application'

android {
compileSdkVersion 26
defaultConfig {
    applicationId "com.example.hp_pc.myapplication"
    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 {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:26.1.0'
implementation 'com.android.support.constraint:constraint-layout:1.0.2'
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'
}