Python test files should not mask ImportErrors

[kytrinyx]

Copied from exercism/exercism#1376 - reported by @hop

Please see the original discussion for details.

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In case there is an import error in the implementation of the exercise, the misleading error message 'Could not find wordcount.py. Does it exist?' is emitted and the original error message is hidden.

I'm not entirely sure what a good alternative would look like, but something like this would be a start:

try:
    from foo import Bar
except ImportError as e:
    raise SystemExit('Could not import foo.py.' 
                     'This was the error: '+str(e))

[betegelse]

My vote is to simply take the try statement out. The traceback is usually short enough (4 lines, a far cry from one of those java tracebacks, for example) and gives the file and line number information to go after the error.

Traceback example:

Traceback (most recent call last):
  File "handshake_test.py", line 1, in <module>
    from handshake import shake, code
ImportError: cannot import name shake

[kytrinyx]

That sounds reasonable to me. I'd say go for it.

[sjakobi]

Fixed with 892c4f2.