Fixing version of nock being used

Recent upstream changes have broken our recordings, fixing the nock version
until there's time to investigate required changes.
Force update of npm on travis

Old versions no longer download dependencies correctly.
Turning node 0.6 build, since new versions of npm don't work
with 0.6.
Yaml syntax fix
Merge pull request #1216 from christav/nock-update-check

Fixing version of nock