Update scancode-toolkit to latest release

[steven-esser]

In order to use things like the VirtualCodebase class, we need the latest scancode-toolkit version.

[johnmhoran]

@MaJuRG After updating and configuring scancode-toolkit, I ran etc/release/release.sh in Git Bash. Several warnings (I can post here if you'd like) but seems to have completed OK.

I've compared the files in C:\code\nexb\dev\deltacode\thirdparty\prod\ and C:\code\nexb\scancode-toolkit\dist\scancode-toolkit-2.9.1\thirdparty\prod looking for updated versions, found two. In addition to replacing scancode_toolkit-2.2.1-py2-none-any.whl with scancode_toolkit-2.9.1-py2-none-any.whl, I made these replacements:

attrs-16.3.0-py2.py3-none-any.whl
attrs-17.4.0-py2.py3-none-any.whl

text_unidecode-1.0-py2.py3-none-any.whl
text_unidecode-1.2-py2.py3-none-any.whl

After finishing the replacements, I ran ./configure.bat -- no problems. Both of our test suites passed in full. I also ran a deltacode JSON output and json2csv conversion before and after the replacements -- the output files looked fine.

About to commit and push.

[steven-esser]

Ok, sounds good