Merge branch 'release/0.2.4' into develop
use namedtuple in basic cases
change environment key names, hold only default
fix trivials
support trailing string if using custom log format.
add user_agent key
Merge branch 'hotfix/accesslog-trailing'
Merge branch 'hotfix/accesslog-trailing' into develop
fix function comment
add sample script to load csv data
Merge branch 'feature/use-namedtuple' into develop
update release version -> 0.2.5
update cover documents
Merge branch 'release/0.2.5'