doc updates for html website

v0.16.0 (rasbt#533)

v 0.15.0 (rasbt#493)

0.14 release (rasbt#463)

Merge pull request rasbt#422 from rasbt/0.13

version 0.13 release

v 0.12.0

Merge pull request rasbt#346 from rasbt/0.11.0

0.11.0 release

Merge pull request rasbt#312 from rasbt/v0.10.0

v0.10.0

Merge pull request rasbt#288 from rasbt/v0.9.1

v 0.9.1 release

version 0.9 (rasbt#267)