Clean up the Travis yaml file.

YAML-Tiny should use good YAML.
Remove eval around require Scalar::Util

The required version of perl is high enough that Scalar::Util should
always be present.  The eval is only needed because we are also checking
the version.  However, if Scalar::Util is broken for some reason, it's
better to die than silence the error.  If we silence the error, later
attempts to load it will only give "Attepting to reload Scalar/Util.pm
aborted", making diagnostics much harder.
Merge pull request #33 from haarg/loud-load-error

Remove eval around require Scalar::Util
changelog for PR#33
simplify BEGIN block
now using [Git::Contributors]
add some keywords to metadata
switch from JSON.pm to JSON::MaybeXS
unneeded slash
keep our namespace clean
add IRC channel to metadata
add test case from https://github.com/ingydotnet/yaml-pm/pull/22
YAML-Tiny-1.64

        [CHANGED]

        - remove silencing of any errors encountered while loading
          Scalar::Util (GH#33, Graham Knop)
        - now using JSON::MaybeXS in tests instead of JSON.pm