Hi!

Today I wanted to build a new library and use auto-changelog. In my package.json I referenced "^2.0.0". Npm installed the new version (2.1.0), which is at first no problem. I have this line in my version script of the pacakge.json: auto-changelog -p && git add CHANGELOG.md.

Running the commands as in the README, will break now my release chain:

$ auto-changelog -p
auto-changelog: 0 version tags found…

TypeError: Cannot read property 'tag' of undefined
    at parseReleases ([...]/node_modules/auto-changelog/src/releases.js:49:33)
    at run ([...]/node_modules/auto-changelog/src/run.js:99:26)

Investigating the code shows that there is an index problem: tags[0] is undefined.

Rolling back to "2.0.0" manually made the auto-changelog package run again, so it seems as if the bug was introduced with the recent version release.