Bump version: 0.6.7-dev → 0.6.7

Bump version: 0.6.6-dev → 0.6.6

Bump version: 0.6.5-dev → 0.6.5

Bump version: 0.6.4-dev → 0.6.4

Bump version: 0.6.3-dev → 0.6.3

Bump version: 0.6.2-dev → 0.6.2

v0.6.1 release

fix travis config and makefile

Bump version: 0.5.7-dev → 0.5.7

Bump version: 0.5.6-dev → 0.5.6