Use -dev suffix for development versions

[wikier]

With the discussion around issue #40, in IRC @joernhees suggested that we could adopt the same workflow than rdflib core uses:

• after a release we up the version but suffix it with -dev
• in the release process the last commit removes the "-dev"

That's http://semver.org conform and all the package management tools will see the "-something" as "pre-release".

What do you think?

[joernhees]

i obviously like it ;)

In [24]: import pip

In [25]: SemVer = pip.util.version.SemanticVersion

In [26]: SemVer('1.6.3') < SemVer('1.6.4-dev') < SemVer('1.6.4')
Out[26]: True

[wikier]

Then we can play with such naming in the following versions.

Thanks @joernhees for the valuable idea.

[joernhees]

;) 👍