kiji-schema: Update versions for Chirashi 1.2.6 release

commit: https://github.com/kijiproject/kiji-schema/commit/b38965d97be17f96de26d034e4e5f1549e6e58c7
kiji-schema-shell: Update versions for Chirashi 1.2.6 release

commit: https://github.com/kijiproject/kiji-schema-shell/commit/6373ce649c3c36dbb89381ef2604131238897a7a
kiji-hive-adapter: Update versions for Chirashi 1.2.6 release

commit: https://github.com/kijiproject/kiji-hive-adapter/commit/ed9c343d374c3182e241358970fbfd7c939448a9