Add latest version to the readme

[vblinden]

Hello,

I added the latest release to the README.md so that people who are following the README will install the latest version.

[sandervanhooft]

Thanks.

Could you change it to ^0.1?

From the composer docs (source):

The ^ operator behaves very similarly but it sticks closer to semantic versioning, and will always allow non-breaking updates. For example ^1.2.3 is equivalent to >=1.2.3 <2.0.0 as none of the releases until 2.0 should break backwards compatibility. For pre-1.0 versions it also acts with safety in mind and treats ^0.3 as >=0.3.0 <0.4.0.

[vblinden]

How can tests fail with a change of a README.md? Can you take a look at it?

[sandervanhooft]

It's a known issue. Travis doesn't share confidential environment variables outside the repo. 🤷‍♂

Will look into other solutions to this later on.