[semver:patch] Ensure fail-if-semver-not-indicated parameter set to true is honored

[yaningo]

Checklist

• [n/a] All new jobs, commands, executors, parameters have descriptions
• [n/a] Examples have been added for any significant new features
• [n/a] README has been updated, if necessary

Motivation, issues

In the dev-promote-from-commit-subject command's definition, the function CheckIncrement relies on a conditional expression to decide whether or no to fail the build if the commit subject doesn't include a SemVer increment:

if [ "$SHOULD_FAIL" == "true" ];then
  exit 1

SHOULD_FAIL is defined as an environment variable of the related step:

SHOULD_FAIL: <<parameters.fail-if-semver-not-indicated>>

However, as the shell environment variable SHOULD_FAIL will only ever resolves to either:

• 1 (if fail-if-semver-not-indicated is set to true)

or

• 0 (if fail-if-semver-not-indicated is set to false)

the expression [ "$SHOULD_FAIL" == "true" ] will always return false, and therefore the fail-if-semver-not-indicated parameter set to true will never be honored.

Description

Modify the aforementioned conditional expression so it references the relevant value of the environment variable, and allows fail-if-semver-not-indicated set to true to be honored.

Fixes #112