Chart dependencies with conditions are cleared when running suite

[longgerr]

When we use dependencies with conditions like the following example, the dependencies which doesn't meet the conditions will be deleted from the Chart object, and won't be reloaded in the next test case's run.

dependencies:
  - name: mysql
    repository: https://kubernetes-charts.storage.googleapis.com
    version: 1.2.0
    condition: mysql.enabled
  - name: redis
    repository: https://kubernetes-charts.storage.googleapis.com
    version: 10.5.7
    condition: redis.enabled

Fix:
Chart's dependencies should be kept before each test's run, and recover after the run to make sure the next test run has the correct dependencies loaded