Switch Travis build to Xenial

[nikic]

Not yet officially documented, but already available. This will unblock the removal of the bundled libzip.

[nikic]

The no longer available libt1-dev package has been removed in cc68711.

[nikic]

One failing test:

========DIFF========
002+ 
002- done!
003+ Warning: PDO::exec(): SQLSTATE[22003]: Numeric value out of range: 1264 Out of range value for column 'label' at row 1 in /home/travis/build/php/php-src/ext/pdo_mysql/tests/pdo_mysql_stmt_getcolumnmeta.php on line 63
004+ [120] + 1] Insert failed, 22003 - array (
005+   0 => '22003',
006+   1 => 1264,
007+   2 => 'Out of range value for column \'label\' at row 1',
008+ )
009+ 
010+ Warning: PDO::exec(): SQLSTATE[22003]: Numeric value out of range: 1264 Out of range value for column 'label' at row 1 in /home/travis/build/php/php-src/ext/pdo_mysql/tests/pdo_mysql_stmt_getcolumnmeta.php on line 63
011+ [130] + 1] Insert failed, 22003 - array (
012+   0 => '22003',
013+   1 => 1264,
014+   2 => 'Out of range value for column \'label\' at row 1',
015+ )
016+ 
017+ Warning: PDO::exec(): SQLSTATE[22003]: Numeric value out of range: 1264 Out of range value for column 'label' at row 1 in /home/travis/build/php/php-src/ext/pdo_mysql/tests/pdo_mysql_stmt_getcolumnmeta.php on line 63
018+ [150] + 1] Insert failed, 22003 - array (
019+   0 => '22003',
020+   1 => 1264,
021+   2 => 'Out of range value for column \'label\' at row 1',
022+ )
023+ 
024+ Warning: PDO::exec(): SQLSTATE[22003]: Numeric value out of range: 1264 Out of range value for column 'label' at row 1 in /home/travis/build/php/php-src/ext/pdo_mysql/tests/pdo_mysql_stmt_getcolumnmeta.php on line 63
025+ [190] + 1] Insert failed, 22003 - array (
026+   0 => '22003',
027+   1 => 1264,
028+   2 => 'Out of range value for column \'label\' at row 1',
029+ )
030+ 
031+ Warning: PDO::exec(): SQLSTATE[22003]: Numeric value out of range: 1264 Out of range value for column 'label' at row 1 in /home/travis/build/php/php-src/ext/pdo_mysql/tests/pdo_mysql_stmt_getcolumnmeta.php on line 63
032+ [230] + 1] Insert failed, 22003 - array (
033+   0 => '22003',
034+   1 => 1264,
035+   2 => 'Out of range value for column \'label\' at row 1',
036+ )
037+ 
038+ Warning: PDO::exec(): SQLSTATE[22003]: Numeric value out of range: 1264 Out of range value for column 'label' at row 1 in /home/travis/build/php/php-src/ext/pdo_mysql/tests/pdo_mysql_stmt_getcolumnmeta.php on line 63
039+ [270] + 1] Insert failed, 22003 - array (
040+   0 => '22003',
041+   1 => 1264,
042+   2 => 'Out of range value for column \'label\' at row 1',
043+ )
044+ 
045+ Warning: PDO::exec(): SQLSTATE[22003]: Numeric value out of range: 1264 Out of range value for column 'label' at row 1 in /home/travis/build/php/php-src/ext/pdo_mysql/tests/pdo_mysql_stmt_getcolumnmeta.php on line 63
046+ [310] + 1] Insert failed, 22003 - array (
047+   0 => '22003',
048+   1 => 1264,
049+   2 => 'Out of range value for column \'label\' at row 1',
050+ )
051+ 
052+ Warning: PDO::exec(): SQLSTATE[22007]: Invalid datetime format: 1292 Incorrect datetime value: '1537192479' for column 'label' at row 1 in /home/travis/build/php/php-src/ext/pdo_mysql/tests/pdo_mysql_stmt_getcolumnmeta.php on line 63
053+ [350] + 1] Insert failed, 22007 - array (
054+   0 => '22007',
055+   1 => 1292,
056+   2 => 'Incorrect datetime value: \'1537192479\' for column \'label\' at row 1',
057+ )
058+ done!
========DONE========
FAIL MySQL: PDOStatement->getColumnMeta() [ext/pdo_mysql/tests/pdo_mysql_stmt_getcolumnmeta.phpt] 

[nikic]

Merged as d2dc0a3 and 70d47b3.