Support CssToInlineStyles 2.2

[hkdobrev]

From #20 (comment)

0.5

✅ Now released! 🎉

• php versions supported: 5.4, 5.5, 5.6, 7.0 and 7.1
• swiftmailer: 5.x
• css-to-inline-styles: 2.1.x

This is the current state of master.

0.6

• php versions supported: 5.6, 7.0, 7.1, 7.2
• swiftmailer: 5.x
• css-to-inline-styles: 2.2.x

0.7 or 1.0.0

• php versions supported: 7.0, 7.1, 7.2
• swiftmailer: 6.x
• css-to-inline-styles: 2.2.x

---

@nclsHart Actually, why should we publish new minor releases locking specific minor releases of the tijsverkoyen/css-to-inline-styles package?

Shouldn't we actually allow different versions as long as there aren't any breaking changes? Or the tests are worrying you as there are quite a few changes to the output in 2.2?

[hkdobrev]

Also, I'd drop PHP 7.0 from 0.7 as its active support has ended and soon the security fixes would stop as well.

[nclsHart]

@hkdobrev You're absolutely right about tijsverkoyen/css-to-inline-styles, there is no need for locking on 2.2.x. We shouldn't have any problem with the latest changes in the tests. Staying on ^2.1 should be ok.

Regarding the dropping of PHP 7.0 in 0.7, I'm more divided. Yes, this version is not in active support anymore but I think staying on the same range of supported versions than swiftmailer could be coherent too.

[hkdobrev]

Staying on ^2.1 should be ok.

OK, I'd try that. We can then release it as 0.5.x version :)

[hkdobrev]

Regarding the dropping of PHP 7.0 in 0.7, I'm more divided. Yes, this version is not in active support anymore but I think staying on the same range of supported versions than swiftmailer could be coherent too.

Fair enough

[nclsHart]

We can then release it as 0.5.x version :)

👍