function isgzipBuffer( value ) {
	if ( !isUint8Array( value ) && !isBuffer( value ) ) {
		return false;
	}
	if ( value.length < 19 ) { // 10-byte header + 8-byte footer + payload
		return false;
	}
	return (
		// Check for expected magic number:
		value[ 0 ] === 0x1F &&
		value[ 1 ] === 0x8B &&

		// Check for expected compression method:
		value[ 2 ] === 0x08
	);
}
Tests if a value is a gzip buffer (or Uint8Array).

@param {*} value - value to test
@returns {boolean} boolean indicating whether a value is a gzip buffer

@example
var Uint8Array = require( '@stdlib/array/uint8' );

var buf = new Uint8Array( 20 );
buf[ 0 ] = 31;  // 0x1f => magic number
buf[ 1 ] = 139; // 0x8b
buf[ 2 ] = 8;   // 0x08 => compression method

var bool = isgzipBuffer( buf );
// returns true

@example
var Uint8Array = require( '@stdlib/array/uint8' );

var bool = isgzipBuffer( new Uint8Array( 20 ) );
// returns false

@example
var bool = isgzipBuffer( [] );
// returns false