Errors in laravel-5 configuration

I got multiple errors while configurating project on laravel (downloading existing project using git and composer).

(1/4) FatalThrowableError

Parse error: syntax error, unexpected 'const' (T_CONST), expecting variable (T_VARIABLE) in PDOStatement.php line 40

(2/4) PDOException

SQLSTATE[HY000]: General error: PDO::ATTR_STATEMENT_CLASS requires format array(classname, array(ctor_args)); the classname must be a string specifying an existing class in PDOConnection.php line 47

(3/4) PDOException

SQLSTATE[HY000]: General error: PDO::ATTR_STATEMENT_CLASS requires format array(classname, array(ctor_args)); the classname must be a string specifying an existing class

in PDOConnection.php line 50

(4/4) QueryException

SQLSTATE[HY000]: General error: PDO::ATTR_STATEMENT_CLASS requires format array(classname, array(ctor_args)); the classname must be a string specifying an existing class (SQL: select * from "users" where "email" = ******** limit 1) in Connection.php line 647

im using php7.1, postgres, apache2 server

migrate database using php artisan

via Chebli Mohamed