WordPress : Load any third-party script locally

footer.php

<?php
/*
In theme's footer, call the locally hosted script file.
*/
?>

<!-- <script type="text/javascript" src="https://static1.clutch.co/api/widget.js" async></script> -->
<script type="text/javascript" src="<?php echo LOCAL_SCRIPTS_UPDLOAD_URL . '/dcg_clutch_widget_local.js'; ?>"></script>

<!-- <script type="text/javascript" src="https://secure.tula9mari.com/js/151014.js" ></script> -->
<script type="text/javascript" src="<?php echo LOCAL_SCRIPTS_UPDLOAD_URL . '/dcg_lead_forensic_local.js'; ?>" async></

functions.php

<?php
//Define uploads directory to store cached/downloaded scripts
$wp_upload_dir = wp_upload_dir();
define( 'LOCAL_SCRIPTS_UPDLOAD_DIR', $wp_upload_dir['basedir'] . '/dcg-locally-stored-scripts' );
define( 'LOCAL_SCRIPTS_UPDLOAD_URL', $wp_upload_dir['baseurl'] . '/dcg-locally-stored-scripts' );

// Create a scheduled event (if it doesn't exist)
function dcg_cron_activate() {
	if( !wp_next_scheduled( 'dcg-get-external-scripts-cron' ) ) {  
		wp_schedule_event( time(), 'daily', 'dcg-get-external-scripts-cron' );  
	}
}
// Activate cron when WordPress loads
add_action( 'wp', 'dcg_cron_activate' );

// Hook the function into scheduled event
add_action( 'dcg-get-external-scripts-cron', 'dcg_file_to_store' );

// Unschedule cron upon plugin deactivation
function dcg_cron_deactivate() {	
	// Find out the last cron event was scheduled
	$timestamp = wp_next_scheduled ( 'dcg-get-external-scripts-cron' );
	// Unschedule previous event if any
	wp_unschedule_event ( $timestamp, 'dcg-get-external-scripts-cron' );
} 
register_deactivation_hook ( __FILE__, 'dcg_cron_deactivate' );

// Initiate the function to store file locally from remote URL
function dcg_file_to_store() {
	// clutch.co widget
	dcg_download_file( 'https://static1.clutch.co/api/widget.js', LOCAL_SCRIPTS_UPDLOAD_DIR . '/dcg_clutch_widget_local.js' );
	// lead forensic tracking
	dcg_download_file( 'https://secure.tula9mari.com/js/151014.js', LOCAL_SCRIPTS_UPDLOAD_DIR . '/dcg_lead_forensic_local.js' );  
}
add_action( 'init', 'dcg_file_to_store' );

// Function that retrieve file from remote server to local
function dcg_download_file( $url, $filename ) {
	if ( !file_exists( LOCAL_SCRIPTS_UPDLOAD_DIR ) && !is_dir( LOCAL_SCRIPTS_UPDLOAD_DIR ) ) {
		mkdir( LOCAL_SCRIPTS_UPDLOAD_DIR );         
	}

    $file = fopen ( $url, "rb" );
    if ( !$file ) return false;
    else {
        $fc = fopen( $filename, "wb" );
        while ( !feof ( $file ) ) {
            $line = fread ( $file, 1028 );
            fwrite( $fc, $line );
        }
        fclose( $fc );
        return true;
    }
}
?>