fix(helm): remove default repos to enable proper config overrides (#136)

Bump go dependencies

Tag images for branches

Port tests to 'stretchr/testify' library

Dependencies bump

Dependencies versions bump

Added mirrorlist config

This commit adds a mirrorlist files regex to parse them and it allows to specify URLs with mirrorlist files.
The mirrorlist URLs list gets updated each time a prefetching routine is being called.

Implements #40.

1.1 Release

Fix revive style warning

"error should be the last type when returning multiple items"