Update to 0.11.4

CHANGES:
0.11.4
    Work with QuickCheck-2.7 (which defines ===)
    #100, handle GraphViz missing gracefully
    Fix up the profiling report generation
    #99, add getEnvWithDefault
0.11.3
    #97, fix a serialisation bug when > 254 arguments to need
( #97 => https://github.com/ndmitchell/shake/pull/97 )
( #99 => https://github.com/ndmitchell/shake/pull/99 )
( #100 => https://github.com/ndmitchell/shake/issues/100 )