Add options to change stream and file log level

[dd-jy]

Change file log level to INFO

Description

(Please describe what this PR do.)
The log file needs to be written more detail information. So please change the file log level to lower level (INFO).

Type of change

Please insert 'x' one of the type of change.

• Bug fix (non-breaking change which fixes an issue)
• [] New feature (non-breaking change which adds functionality)
• Documentation update
• Refactoring, Maintenance
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

[soimkim]

Dear @dd-jy ,

fosslight_util supports python 3.6+ and
pathlib is known to be included in the built-in module since Python 3.4.

Should it be included in the requirements.txt?

[dd-jy]

It's my mistake. I tested python2.x.
I removed the last commit.

[soimkim]

Dear @dd-jy ,

If you want to distribute this to pypi, also upload the commit to upgrade version in setup.py.
And if you release after merge, it is also distributed to pypi.

[soimkim]

@dd-jy , LGTM. :-)