Unable to resolve dependency for ':app@debugUnitTest/compileClasspath': Could not resolve com.android.support.constraint:constraint-layout:1.0.1.

Could not resolve com.android.support.constraint:constraint-layout:1.0.1.
Required by:
    project :app
 > Could not resolve com.android.support.constraint:constraint-layout:1.0.1.
    > Could not get resource 'https://dl.google.com/dl/android/maven2/com/android/support/constraint/constraint-layout/1.0.1/constraint-layout-1.0.1.pom'.
          > Could not GET 'https://dl.google.com/dl/android/maven2/com/android/support/constraint/constraint-layout/1.0.1/constraint-layout-1.0.1.pom'.
                   > sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
                               > PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
                                              > unable to find valid certification path to requested target

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

buildscript {
    repositories {
        jcenter() {
            url "http://jcenter.bintray.com/"
        }
        google()
//        mavenCentral()
//        maven()
//                {
//                    url "http://maven.google.com"
//                }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.0'

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

allprojects {
    repositories {
        jcenter() {
            url "http://jcenter.bintray.com/"
        }
        google()
//        mavenCentral()
//        maven()
//                {
//                    url "http://maven.google.com"
//                }
    }
}

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



Here is my Build.gradle file(app) :

apply plugin: 'com.android.application'

android {
    compileSdkVersion 25
    defaultConfig {
        applicationId 'com.example.hellojnicallback'
        minSdkVersion 21
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'),
                          'proguard-rules.pro'
        }
    }
    externalNativeBuild {
        cmake {
            path "src/main/cpp/CMakeLists.txt"
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:25.4.0'
    implementation 'com.android.support.constraint:constraint-layout:1.0.1'
}

buildscript {
    repositories {
        jcenter() {
            url "https://jcenter.bintray.com/"
        }
        mavenCentral()
        maven { url 'http://maven.fabric.io/public' }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.2.2'
        classpath 'io.fabric.tools:gradle:1.+'
    }
}

apply plugin: 'com.android.application'
apply plugin: 'io.fabric'


repositories {
    jcenter() {
        url "https://jcenter.bintray.com/"
    }
    mavenCentral()
    maven { url 'http://maven.fabric.io/public' }
}

android {
    compileSdkVersion 23
    buildToolsVersion "23.0.2"

    defaultConfig {
        applicationId "com.javacodegeeks.androidcrashlyticsexample"
        minSdkVersion 14
        targetSdkVersion 23
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:23.2.1'
    **compile('com.crashlytics.sdk.android:crashlytics:2.5.5@aar') {**
        transitive = true;
    }
}


So I think the issue is in the URL , and this particular URL - from the maven where the AS 3.0 is trying to fetch is being blocked by my corporate firewall.Is it so?