Moving import paths back to "upper.io/db"

.travis.yml

README.md

db.go

db_test.go

mongo/README.md

mongo/_example/main.go

mongo/collection.go

mongo/connection.go

mongo/connection_test.go

mongo/database.go

mongo/database_test.go

mongo/result.go

mysql/README.md

mysql/_example/main.go

mysql/collection.go

mysql/connection.go

mysql/connection_test.go

mysql/database.go

mysql/database_test.go

mysql/mysql.go