Fix python styling and flake8 issues

[Flamefire]

This makes flake8 pass.

The renaming of the config file is so it is automatically recognized by autopep8 and flake8. Another (maybe better) solution is to rename to setup.cfg which also works with both tools.

Most of the issues have been fixed by running autopep8. The remainder has been manually fixed

For reference the found issues are:

benchmark/benchmark_helper.py:43:18: E211 whitespace before '('
benchmark/benchmark.py:13:7: E225 missing whitespace around operator
benchmark/benchmark.py:14:20: E225 missing whitespace around operator
benchmark/benchmark.py:15:20: E225 missing whitespace around operator
benchmark/benchmark.py:15:71: W291 trailing whitespace
benchmark/benchmark.py:21:12: F632 use ==/!= to compare constant literals (str, bytes, int, float, tuple)
scorep/__main__.py:123:121: E501 line too long (127 > 120 characters)
scorep/__init__.py:2:1: F401 'scorep.instrumenter' imported but unused
scorep/instrumenter.py:20:121: E501 line too long (129 > 120 characters)
scorep/instrumenter.py:50:121: E501 line too long (125 > 120 characters)
scorep/instrumenter.py:65:121: E501 line too long (129 > 120 characters)
scorep/instrumenter.py:106:121: E501 line too long (129 > 120 characters)
scorep/instrumenters/dummy.py:5:1: E302 expected 2 blank lines, found 1
test/test.py:301:9: F841 local variable 'trace_path' is assigned to but never used
test/test.py:319:9: F841 local variable 'expected_std_err' is assigned to but never used
test/test.py:320:30: W605 invalid escape sequence '\['
test/test.py:320:38: W605 invalid escape sequence '\]'
test/test.py:320:41: W605 invalid escape sequence '\['
test/test.py:320:57: W605 invalid escape sequence '\]'
test/test.py:320:62: W605 invalid escape sequence '\['
test/test.py:320:72: W605 invalid escape sequence '\['
test/test.py:320:88: W605 invalid escape sequence '\]'
test/test.py:323:27: W605 invalid escape sequence '\['
test/test.py:323:36: W605 invalid escape sequence '\]'
test/test.py:323:40: W605 invalid escape sequence '\w'
test/test.py:331:9: F841 local variable 'trace_path' is assigned to but never used
test/test.py:349:9: F841 local variable 'trace_path' is assigned to but never used
test/test.py:385:1: W293 blank line contains whitespace
test/test.py:387:9: E303 too many blank lines (2)
test/test.py:398:5: E303 too many blank lines (2)
test/test_user_instrumentation.py:10:1: E305 expected 2 blank lines after class or function definition, found 1
test/test_instrumentation.py:9:1: E305 expected 2 blank lines after class or function definition, found 1
test/test_numpy_dot.py:5:16: E231 missing whitespace after ','
test/test_numpy_dot.py:5:24: W291 trailing whitespace
test/test_numpy_dot.py:6:16: E231 missing whitespace after ','
test/test_numpy_dot.py:7:1: W293 blank line contains whitespace
test/test_numpy_dot.py:8:20: E231 missing whitespace after ','
test/test_numpy_dot.py:9:13: W292 no newline at end of file

[AndreasGocht]

Agreed, but blocked by #68. As requested, I'll merge this once #68 is merged.