Update README.md

Extended year range
Add pdb files to the nuspec #262
Merge pull request #264 from twiernik/master

Add pdb files to the nuspec #262
sql-insert, sql-update, sql-delete into join
Added tests for sql-update and sql-delete (join)
Merge pull request #265 from Micha-kun/master

sql-insert, sql-update, sql-delete into join
Fix for bug #231
Merge pull request #267 from Micha-kun/master

Fix for bug #231