Added Dashlane, Keeper, Persowna, and SecureSafe

See #448
Corrected image format for Keeper
Added images and exceptions

I couldn't find an image for Persowna so I removed the reference to
that.
Corrected Dashlane
Merge pull request #539 from jamcat22/patch-3

Added Dashlane, Keeper, Persowna, and SecureSafe