Drhuffman12/upgrade to crystal 1.1.1 (and 1.2.0-dev)

[drhuffman12]

-[x] Add dependency of crystal-lang/json_mapping.cr/ (JSON.mapping was deprecated and moved to shard.)

• Drop deprecated JSON.mapping crystal-lang/crystal#9527
• https://github.com/crystal-lang/json_mapping.cr

-[x] Add more environment variables for database connection settings with defaults.

• For now, just for tests:

    un = ENV.keys.includes?("TEST_DB_UN") ? ENV["TEST_DB_UN"] : "admin"
    pw = ENV.keys.includes?("TEST_DB_PW") ? ENV["TEST_DB_PW"] : "password"
    ip = ENV.keys.includes?("TEST_DB_IP") ? ENV["TEST_DB_IP"] : "localhost"
    port = ENV.keys.includes?("TEST_DB_PORT") ? ENV["TEST_DB_PORT"] : "5984"
    couchdb_url = ENV.keys.includes?("TEST_DB") ? ENV["TEST_DB"] : "http://#{un}:#{pw}@#{ip}:#{port}"
  

-[x] DEPRECATION: Use ServerInfo#version instead of Vendor#version.
As of v3.x (or earlier?), a call to the server's root (e.g.: GET http://127.0.0.1:5984/)
no longer returns version inside vendor.
In v3.x, response will instead look like:

{
  "couchdb":"Welcome",
  "version":"3.1.1",
  "git_sha":"ce596c65d",
  "uuid":"SOME_UUID_GOES_HERE",
  "features":["access-ready","partitioned","pluggable-storage-engines","reshard","scheduler"],
  "vendor":{"name":"The Apache Software Foundation"}
}

-[x] Allow 3.x.x versions of CouchDB.

• Add is_v2? and is_v3? methods to CouchDB::Response::ServerInfo.

-[x] Remove hard-coded crystal key/version from shard.yml (for now).

• Tested (and passed)
  • locally w/ Crystal 1.1.1 [6d9a1d583] (2021-07-26)
  • via CircleCI w/ Crystal 1.2.0-dev [cadc4b3c7] (2021-09-02)

-[x] Bump version of this shard to 0.4.0

• Set CouchDB::VERSION based on shard version value in from shard.yml (to avoid out-of-sync issues).

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Next steps... see also:

• Drhuffman12/upgrade to crystal 1.1.1 (and 1.2.0-dev) (#1) and expand CouchDB version checks vectorselector/couchdb.cr#2
• Update to more recent Crystal and CouchDB versions TechMagister/couchdb.cr#13
• Expand CI to check against various combo's of Crystal, CouchDB, and (backend) OS TechMagister/couchdb.cr#14
• Create/link to sample app TechMagister/couchdb.cr#15