Add memcached backend (mennanov#33)

* add LockMemcached

* add LeakyBucketMemcached

* add TokenBucketMemcached

* add ConcurrentBufferMemcached

* add FixedWindowMemcached

* add SlidingWindowMemcached

* Refactor and reorder the code and document

* Refactor and reorder the code and document

* remove suffix from prefix

* add Memcached to README.md

* expose backoff in NewLockMemcached

* add LockMemcached.WithLockAcquireBackoff()

Add redsync Mutex options for LockRedis and use context in LockRedis (m…

…ennanov#31)

Clear lastVersion in a case of returning an empty TokenBucketState (m…

…ennanov#30)

Bump golang.org/x/net from 0.7.0 to 0.17.0 (mennanov#27)

Bumps [golang.org/x/net](https://github.com/golang/net) from 0.7.0 to 0.17.0.
- [Commits](golang/net@v0.7.0...v0.17.0)

---
updated-dependencies:
- dependency-name: golang.org/x/net
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Fix a mistake of redis ttl (mennanov#22)

implement redis lock using redsync (mennanov#15)

Signed-off-by: Guillaume Delbergue <guillaume.delbergue@hiventive.com>

Add DynamoDB limiter backend (mennanov#13)

Account for partial tokens in token bucket by truncating Last to rate (…

…mennanov#12)

* fix: account for partial tokens in token bucket by truncating time to rate

* add test for token bucket refill

* test changes

---------

Co-authored-by: Jacob Lambert <jacob@jacoblambert.com>

Make Unlock context aware (mennanov#7)

* Make Unlock context aware

Migrate to google.golang.org/protobuf