Allow vectors l and u to be NULL. This fixes the issue introduced in o…

…sqp#215 that makes the matlab tests not pass. osqp/osqp-matlab#32

Bump version: 0.6.0 → 0.6.2.dev0

Bump version: 0.6.0.dev20 → 0.6.0

Added changelog date

Added bintray override to package deployment

Updated travis

Merge branch 'dev-0.3.1' of https://github.com/oxfordcontrol/osqp int…

…o dev-0.3.1

Bump version: 0.3.0.dev1 → 0.3.0

Bump version: 0.2.1.dev1 → 0.2.1

Bump version: 0.2.0.dev10 → 0.2.0