* minor refactoring and a bit more test coverage

* use drone for tests

* remove old glide config file

* remove circleCi config

* Streams metrics support.

There are new key type in Redis 5 - Streams.
So, we get ability to monitor them.

* Test for stream.

* Update openshift yaml to use the source repo references.

* Update README.md to point to source repo for consistency.

* Fix broken link in README.md

* Enable support for having the redis password in a file

* Update readme

* run instructions

* add link to sample redis file

* Avoid using KEYS.

* Check single keys, or patterns with `SCAN`

Continues the work that @Tinche did in #149.

* Add an arg, `check-single-keys` to get size and value with `TYPE`
* Modify the behavior of `check-keys`
  * Get keys from globs with `SCAN` rather than `KEYS`
  * If a key doesn't have any glob characters in it, just add it to the
    list of things to check with `TYPE`

I added an argument rather than decide `SCAN` vs `TYPE` based on the
presence of glob characters because, technically, redis key names can
contain glob characters, according to https://redis.io/topics/data-types-intro:

    Redis keys are binary safe, this means that you can use any binary
    sequence as a key, from a string like "foo" to the content of a JPEG
    file. The empty string is also a valid key.

The only way to be able to check for key names with glob characters in
them is by being able to explicitly specify keys that you don't want to
glob for.

Allow an optional Redis Lua script to collect extra metrics.

This can be enabled with a new `-script` flag. An example is provided in
contrib.

This allows one to manage a file separately from the service definition
and simply restart the service once the configured file is updated.

dd flag -redis.alias. Allow to give an alias to the redis node(s) address. It could be more friendly (especially in graph) to display the alias than just the node address. Add a modified dashboard for Grafana.

Adds the "redis.password" flag, which allows for authenticating
connections to the Redis server or servers. This flag defaults
to the environment variable `REDIS_PASSWORD`.

To simplify the function signatures, a RedisHost structure was implemented
to contain all information about the connection to Redis.