Handle file magic type varying order matching

Allow file test to return all possible mime-types and ensure anything
that matches the python file type is parsed by flake8 instead of
relying on the first match returned.

Closes-Bug: #1585688
Change-Id: Iba31f1853537fe9234ab6f83d66f13dc1c578abb

bin/dib-lint

@@ -80,7 +80,7 @@ for i in $(find elements -type f   \
         fi
 
         # Ensure 4 spaces indent are used
-        if [ "$(file -b --mime-type $i)" = "text/x-python" ]; then
+        if [[ "$(file -b -k --mime-type $i)" =~ "text/x-python" ]]; then
             flake8 $i || error "$i failed flake8"
         else
             if ! excluded indent ; then