Do not apply journal and show warning message for chewy:reset and chewy:upgrade if journal index is missing

[konalegi]

Description

During rake chewy:reset with disabled journaling we get the following error

Chewy – [404] {"error":{"root_cause":[{"type":"index_not_found_exception","reason":"no such index [chewy_journal]","resource.type":"index_or_alias","resource.id":"chewy_journal","index_uuid":"na","index":"chewy_journal"}],"type":"index_not_found_exception","reason":"no such index [chewy_journal]","resource.type":"index_or_alias","resource.id":"chewy_journal","index_uuid":"na","index":"chewy_journal"},"status":404}

This doesn't say that there is an error, just journal index is missing, but it confuses some developers who are not familiar with chewy and make them think that there is an import error.

New behavior disables replay of the journal from old index if there is no journal and additionally show warning message

$ be rake chewy:reset

##########################################################
WARN: You are risking to lose some changes during the reset.
      Please consider enabling journaling.
      See https://github.com/toptal/chewy#journaling
##########################################################
Resetting IndexOne
  Imported IndexOne in 1s, stats: index 932
  Imported Chewy::Stash::Specification in 1s, stats: index 1
Resetting IndexTwo
....

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• Added tests.
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