Release version 1.6.1

Merge branch 'master' of https://github.com/eiichiro-oiwa/ImmutableSt…

…orage into b1

Release version 1.6.0

Merge branch 'master' of https://github.com/eiichiro-oiwa/ImmutableSt…

…orage into b1

Release version 1.5.0

Merge branch 'master' of https://github.com/eiichiro-oiwa/ImmutableSt…

…orage into b1

Release version 1.4.0

Merge branch 'master' of https://github.com/eiichiro-oiwa/ImmutableSt…

…orage into b1

Release version 1.3.1

Merge branch 'master' of https://github.com/eiichiro-oiwa/ImmutableSt…

…orage into b1

Release version 1.3.0

Merge branch 'master' of https://github.com/eiichiro-oiwa/ImmutableSt…

…orage into b1

Release version 1.2.1

Merge branch 'master' of https://github.com/eiichiro-oiwa/ImmutableSt…

…orage into b1

Release version 1.2.0

Merge branch 'master' of https://github.com/eiichiro-oiwa/ImmutableSt…

…orage into b1

v1.1.0

Release version 1.1.0

v1.0.1

Release version 1.0.1