Don't claim the outcome of an unfinished build is 'failed'

This moves the 'build-state' span before the 'build-success' one to make
it more obvious that the build is still running. It also changes the
text of the 'build-success' span to 'Not yet finished' if the build
state is not 'finished'.
Merge pull request #354 from mineo/build-state-not-finished

Don't claim the outcome of an unfinished build is 'failed'