Merge pull request oracle#17 from oracle/2.6.x Release version 2.6.8

Merge pull request oracle#16 from oracle/2.6.x Release version 2.6.7

Merge pull request oracle#14 from oracle/2.6.x Release version 2.6.6

Merge pull request oracle#13 from oracle/2.6.x Release version 2.6.5

Merge pull request oracle#12 from oracle/2.6.x Release version 2.6.4

fix readthedocs requirement 

Merge pull request oracle#9 from oracle/2.6.x Release version 2.6.2

Merge pull request oracle#8 from oracle/2.6.x Release version 2.6.1

Merge pull request oracle#7 from oracle/2.5.x Release version 2.5.10

Merge pull request oracle#4 from oracle/2.5.x 2.5.x