allow raw Postgres connection string
use new constructors in profiles/benchmarks
Raise the lower bound of "transformers"
Merge branch 'master' into pr/8

* master:
  Raise the lower bound of "transformers"
  Increment the minor version
  Update Travis
  Update Travis
  Test the lower bound of "hashtables"
  Update the Travis config
  Test a wrong port
  Clean up
  Update the lower boundary of "transformers" in the Travis config
  Relax the "hashtables" dependencies
  Drop redundant tests
Corrections
Ditch the text
Increment the major version
Merge branch 'pr/8'

* pr/8:
  Increment the major version
  Ditch the text
  Corrections
  use new constructors in profiles/benchmarks
  allow raw Postgres connection string