Fixed delete edge rule path value to string for guid

[ToshY]

Fixes #134

[ToshY]

Works now. Documentation already correct.

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When testing noticed that the addOrUpdateEdgeRule both handles add and update and has several required keys set, but the majority of those are only relevant for adding a new rule. Updating a rule only seems to require the Guid and atleast 1 Triggers (else it results in {"ErrorKey":"edgerule.invalid","Field":"EdgeRule","Message":"At least one condition is required"}).

So need to create follow-up enhancement for that.