FileNotFoundError is raised when task running with gokart.build() failed

[mski-iksm]

The following code with error in run() will exit with FileNotFoundError instead of NotImplementedError.

class Example(gokart.TaskOnKart):        
    def run(self):
        raise NotImplementedError("not implemented")

task = Example(rerun=True)
gokart.build(task)

>>> FileNotFoundError: [Errno 2] No such file or directory: './resources/__main__/Example_8441c59b5ce0113396d53509f19371fb.pkl'

[vaaaaanquish]

similer: #224, #209

[Hi-king]

#237 must have solved this issue :) @mski-iksm