remove Git2\ODB::addBackend and Git2\ODB::addAlternate methods.
remove Git2\ODB::addBackend and Git2\ODB::addAlternate methods.

these methods does not expect hotswap backends. will be add
`Git2\ODB Git2\ODB::withBackends(array $backends[, array $alternate_backends])` instead of these.

garvins/php-git,libgit2/php-git,MagicalTux/php-git,MagicalTux/php-git,garvins/php-git,MagicalTux/php-git,garvins/php-git,garvins/php-git,libgit2/php-git,libgit2/php-git