Let pbGetPosts use UTF-8 encoding

[mrchypark]

pbGetPosts is more suitable.

And fix encoding issue on windows non-english language.

I'm sorry don't understand your test code. how do I add test?

[eddelbuettel]

As you saw, I had already made the change adding the plural 's' to pbGetPosts

Adding encoding is useful. I'll merge that as a quick squash merge as your fork was out of sync anyway.

Tests can be simple. By default, during R CMD check every file ending in .R in the tests/ directory is executed. We already have tests/simpleTests.R so it was mostly a suggestion to add two or three lines to attempt to run pbGetPosts() (after having posted something) to see if we get something back, as one would expect. But I released by now anyway so no hurry.