Added Logic to check existence of Secrets for ChaosExperiments

[christopherfriedrich]

Signed-off-by: christopherfriedrich christopher.friedrich@haw-hamburg.de

What this PR does / why we need it:

• Checks the existence of the referenced Secrets in all ChaosExperiments and reports the missing ones

Which issue this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged): fixes #14

Special notes for your reviewer:

Checklist:

• Fixes Add validation for ChaosExperiment's Secrets #14
• Labelled this PR & related issue with documentation tag
• PR messages has document related information
• Labelled this PR & related issue with breaking-changes tag
• PR messages has breaking changes related information
• Labelled this PR & related issue with requires-upgrade tag
• PR messages has upgrade related information
• Commit has unit tests
• Commit has integration tests

[christopherfriedrich]

I want to add some unit tests this time with regard to #2, but i'm unsure how to name the corresponding file webhook_test or appFilterCheck_test ?

[rahulchheda]

Hey @christopherfriedrich , I was thinking to follow up with an issue on that conversation, but thanks for understnding the context, and getting a PR out of it.
For tests, I think the betterway would be just add unit tests, for appFilterCheck.go i.e appFilterCheck_test.go. Let me know if you need any help for it.

[rahulchheda]

/lgtm