tests for global.image.pullSecretNames

[caleblloyd]

Tests for #814

Changes un-released global.image.pullSecrets to global.image.pullSecretNames

This is because imagePullSecrets takes an array of {name: secretName} objects

I thought it was better to be more specefic that we are only taking the secretName portion in pullSecretNames, and we are adding the name: key

This is consistent with the use of secretName many other places in the chart values

[caleblloyd]

/cc @adberger

[adberger]

/cc @adberger

I'm fine with that, thanks.
Just FYI the other helm charts also don't seem to template name automatically.