Add installedVersion format option

[jakubdrozdek]

A new format option called exactCurrentVersion has been added. This option replaces the usual version range copied from the project's package.json file with the exact version of the installed package. For instance, this feature might be helpful if you need to generate a release changelog gist for the updated package.

[jakubdrozdek]

@raineorshine Seems like the tests for getIgnoredUpgradesDueToEnginesNode rely on the actual data returned from the NPM registry, and are flaky - if you'd run them again in a month, they might fail with no changes in the code.

[raineorshine]

A new format option called exactCurrentVersion has been added. This option replaces the usual version range copied from the project's package.json file with the exact version of the installed package. For instance, this feature might be helpful if you need to generate a release changelog gist for the updated package.

Thanks! Let's rename this to installedVersion if you don't mind. It's shorter and it makes it clear that this feature depends on the installed packages in node_modules, which not every package manager supports.

@raineorshine Seems like the tests for getIgnoredUpgradesDueToEnginesNode rely on the actual data returned from the NPM registry, and are flaky - if you'd run them again in a month, they might fail with no changes in the code.

Thanks for bringing this to my attention. We should definitely mock those requests.