title: Gradle can't resolve any of my dependencies
body: <p>For some reason gradle can't resolve any of my dependencies. This is an example: </p>
  
  <p><strong>Module:</strong> </p>
  
  <pre><code>apply plugin: 'com.android.application'
  
  android {
      compileSdkVersion 24
      buildToolsVersion "24.0.2"
      defaultConfig {
          applicationId "app.simplelogin"
          minSdkVersion 15
          targetSdkVersion 24
          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(dir: 'libs', include: ['*.jar'])
      androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
          exclude group: 'com.android.support', module: 'support-annotations'
      })
  
      compile 'com.android.support:appcompat-v7:24.2.1'
      compile 'com.squareup.okhttp3:okhttp:3.0.1'
      testCompile 'junit:junit:4.12'
  }
  </code></pre>
  
  <p><strong>Project:</strong> </p>
  
  <pre><code>buildscript {
      repositories {
          jcenter()
      }
      dependencies {
          classpath 'com.android.tools.build:gradle:2.2.0'
  
          // NOTE: Do not place your application dependencies here; they belong
          // in the individual module build.gradle files
      }
  }
  
  allprojects {
      repositories {
          jcenter()
          mavenCentral()
      }
  }
  
  task clean(type: Delete) {
      delete rootProject.buildDir
  }
  </code></pre>
  
  <p>When I try to sync or build, I get the following error: </p>
  
  <pre><code>Failed to resolve: com.squareup.okhttp3:okhttp:3.0.1
  </code></pre>
  
  <p>I get this same error message with every dependency I try to add - anyone know why? </p>