service - support custom strategies about unleash

[ivarconr]

The whole idea behind an activation strategy is to share it between multiple toggles (or even change strategy for a toggle when it is time to release it).

One concrete example:

• Develper Hans protects new feature with the AwsomeFeature feature toggle.
• Hans enables the feature for his team and product owner in production to show the not completed feature to get som feeback.
• Product owner gives feedback on some important improvements.
• Hans implements improvements.
• The team decides to test the new feature on some real users and changes activation strategy for AwsomeFeature to GradualRolloutStrategy.
• The feature behaves good and they activates it for everyone.
• Hans removes the feature toggle from the code and from unleash.

[jarib]

Jeg ser på mulighet til å legge til nye strategier.