rel(network-agent): Prepare chart version to v0.2.0 (#325)

## Which problem is this PR solving?
Prepares the next version of the agent to be published.

## Short description of the changes
- Updates chart version to 0.2.0

## How to verify that this has the expected result
The next version of the chart can be published.

charts/network-agent/Chart.yaml

@@ -1,7 +1,7 @@
 apiVersion: v2
 name: network-agent
 description: Honeycomb Network Agent
-version: 0.1.1
+version: 0.2.0
 appVersion: v0.1.0-beta
 home: https://honeycomb.io
 sources: