Fix test errors and warnings

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I was unable to run the tests:

• methods.navigate failed due to the method requiring a DOM event as a second parameter
• Many tests showed the duplicate key warning warning which is also visible in the browser console
• Nuxt failed with TypeError: Cannot read property 'emit' of undefined due to @nuxtjs/[email protected] not locking down dependencies and accidentally requiring some non-compatible @[email protected] packages

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Resolves #31

DCO 1.1 Signed-off-by: Thomas Jaggi <[email protected]>

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@Snugug, since you have been merging the last few PRs: Would you be willing to review this one? Thanks in advance!