docs: correct example link to reference proper directory

- Update the example link to reference the correct _example directory

Signed-off-by: appleboy <[email protected]>

docs: clarify project title and improve documentation navigation

- Update project title to "Cache middleware" for clarity
- Add a detailed table of contents to improve navigation

Signed-off-by: appleboy <[email protected]>

fix: improve error handling and update Go linting and workflow

- Update golangci-lint action to version `v7` in the GitHub workflow file
- Remove trailing periods from error messages in `cache_store.go`
- Update method calls in `memcached_binary.go` to use local methods instead of `s.Client`
- Check for errors on closing connections and log them in `memcached_test.go`
- Import `fmt` package in `redis.go`
- Check for errors on closing connections and log them in `redis.go`
- Wrap connection close operations inside a defer func to handle errors in `redis.go`
- Handle errors when closing connections and flushing cache in `redis_test.go`

Signed-off-by: appleboy <[email protected]>

test: add comprehensive tests for serialization and deserialization f…

…unctions

- Add test file `serialzer_test.go` for serialization and deserialization functions
- Implement tests for `Serialize` function with various data types
- Implement tests for `Deserialize` function with various data types
- Add tests for gob encoding and decoding with a custom struct

Signed-off-by: appleboy <[email protected]>

build: refactor build and release configurations

- Update the `go-version` to be read from `go.mod`
- Change the release arguments to `release --clean`
- Add a new file `.goreleaser.yaml` with configuration settings for builds and changelog categories

Signed-off-by: Bo-Yi Wu <[email protected]>

remove .travis.yml

add go module testing

Signed-off-by: Bo-Yi Wu <[email protected]>

Travis