--lint level does not affect junit (or json) output

[shane-kearns]

Version:

v0.6.1

Steps to reproduce:

popeye -l error -o junit

Expected:

Only issues with "error" severity are reported

Observed:

All issues are reported as test failures, e.g.
<failure message="[POP-301] Connects to API Server? ServiceAccount token is mounted" type="warn"></failure>

Impact:

Running of popeye as part of a CI pipeline (e.g. Jenkins) is difficult without post-processing the output.