Add PSR-15 middleware

Merge remote-tracking branch 'origin/master'

Merge pull request odan#3 from diwms/master

Middleware improvement

Add session middleware

Fix test

Renamed repository to odan/session

Merge pull request #1 from odan/analysis-86DwQa

Apply fixes from StyleCI

Merge pull request #1 from odan/analysis-86DwQa

Apply fixes from StyleCI

Removed middleware (use a custom middleware callback instead)

Updated docs