Update nikolaposa/version to version 4

[kevin-lot]

@dontub

I have a question.
Why do you keep the old version of nikolaposa/version (v2 and v3) ?
dependencies of nikolaposa/version are:

• v4 => beberlei/assert and php ^7.2 (so you can upgrade your package to php 7.2, too)
• v3 => php ^7.2 (so you can upgrade your package to php 7.2, too)
• v2 => php ^5.5 (this time, it's shivas/versionning that locks to php 7.1)

So, to put it in a nutshell,
If you want to keep shivas/versionning compatible with php 7.1, version 2 of nikolaposa/version is mandatory.
Without it, only version 4 of nikolaposa/version is required.

[dontub]

I see no need to keep compatibility with PHP 7.1. When updating to nikolaposa/version v4, keeping compatibility with v2/v3 would make the code unnecessarily more complex.

[kevin-lot]

So I removed v2 and v3 of nikolaposa/version.
I tried to update travis too.

[dontub]

VersionBumpCommand needs to be changed, too.

[kevin-lot]

Sorry about the "else" and "elseif".
This is a job conditionning, in my company, we don't allow to code with "else" or "elseif". 😄

[dontub]

I'd suggest to add a method private function transformPreRelease(string $preRelease): ?string { ... }. This would allow to immediately return and thus to avoid the elses. WDYT?

Do you have time to update VersionBumpCommand, too?

[kevin-lot]

Do you have time to update VersionBumpCommand, too?

Done.

[kevin-lot]

I'd suggest to add a method private function transformPreRelease(string $preRelease): ?string { ... }. This would allow to immediately return and thus to avoid the elses. WDYT?

I have to take a look to do with methods.
By the way, I think this is a good idea.

[dontub]

Thanks for contribution @kevin-lot!