Improve performance by using Moo instead of Moose

Hi Philip

Thanks for open sourcing this module - I'm finding it very useful in a current project.

How would you feel about using Moo instead of Moose? I've run some tests and it appears to run a bit faster. My project will run PDF::WebKit inside a Mojo app so the performance improvement would be useful.

I'm not sure of the best way to quantify the improvement but here are the outputs of 5 runs of the test suite with Moose vs with Moo:

With Moose:

    $ prove -Mlocal::lib=local -l
    t/pdf-webkit-integration.t .. ok
    t/pdf-webkit-source.t ....... ok
    t/pdf-webkit.t .............. ok
    All tests successful.
    Files=3, Tests=45,  2 wallclock secs ( 0.03 usr  0.00 sys +  0.91 cusr  0.16 csys =  1.10 CPU)
    Result: PASS
    
    Files=3, Tests=45,  2 wallclock secs ( 0.03 usr  0.00 sys +  0.92 cusr  0.17 csys =  1.12 CPU)
    Files=3, Tests=45,  2 wallclock secs ( 0.03 usr  0.00 sys +  0.92 cusr  0.16 csys =  1.11 CPU)
    Files=3, Tests=45,  2 wallclock secs ( 0.03 usr  0.01 sys +  0.91 cusr  0.16 csys =  1.11 CPU)
    Files=3, Tests=45,  2 wallclock secs ( 0.03 usr  0.01 sys +  0.99 cusr  0.18 csys =  1.21 CPU)

With Moo:

    $ prove -Mlocal::lib=local -l
    t/pdf-webkit-integration.t .. ok
    t/pdf-webkit-source.t ....... ok
    t/pdf-webkit.t .............. ok
    All tests successful.
    Files=3, Tests=45,  2 wallclock secs ( 0.03 usr  0.01 sys +  0.55 cusr  0.12 csys =  0.71 CPU)
    Result: PASS
    
    Files=3, Tests=45,  2 wallclock secs ( 0.03 usr  0.00 sys +  0.49 cusr  0.11 csys =  0.63 CPU)
    Files=3, Tests=45,  2 wallclock secs ( 0.03 usr  0.01 sys +  0.51 cusr  0.12 csys =  0.67 CPU)
    Files=3, Tests=45,  2 wallclock secs ( 0.03 usr  0.01 sys +  0.49 cusr  0.11 csys =  0.64 CPU)
    Files=3, Tests=45,  2 wallclock secs ( 0.03 usr  0.01 sys +  0.51 cusr  0.12 csys =  0.67 CPU)

Please let me know your thoughts. Also note that I have replaced the "no Moose" lines with "use namespace::clean".

Thanks in advance,
Keith