Fixed typo in postgis-scripts package name

[amitpdev]

No description provided.

[lhoss]

Like noted in #156 (comment)
it's strange that the travis build failed for a number of postgres versions (but worked for all postgres versions, when ansible v2 was used!)

👍 to get the travis build re-run and this PR merged (maybe with a renamed title), allowing to close some duplicate issues/PR's and a lot of forks!
@farridav ?

[sebalix]

This is the CentOS build which is failing. Don't know why.

[otakup0pe]

I think the builds failed because distributed systems are complex. Sorry for not restarting them earlier!