update changelog

update version 0.2.6 -> 0.2.7

Merge pull request #55 from EndouMari/r0_2_6

merge r_0_2_6

Merge pull request #49 from EndouMari/r0_2_5

merge r0_2_5

Merge pull request #45 from EndouMari/r_0_2_4

merger r0_2_4

Merge pull request #40 from EndouMari/r_0_2_3

update 0.2.2 -> 0.2.3

Merge pull request #38 from EndouMari/r0_2_2

update 0.2.1 -> 0.2.2

update scheme

update version 0.1.1 -> 0.2.0

Release 0.1.1