Upgrade node and dependencies (#1578)

* upgrade workflow actions

* fix setup-node version

* change redis-64 version to 3.0.503

* fix "no password is set" for redis6,
fix tests to work with redis6,
add redis6 to workflows

* do not use assert.match (was added only at v13.6.0 & v12.16.0)

* fix errors.subscribeUnsubscribeOnly regex

* fix invaliodPassword typo

* send --save "" to redis-server in tests

* upgrade dependencies, set node minimum version to 10, use current LTS versions in tests and benchmark workflows

* change windows tests too

* revert mocha back to ^4.1.0

* fix for f5528504a0 - revert mocha back to ^4.1.0

* fix some tests and upgrade mocha

* fix two more tests

* try to fix tests in windows

* upgrade denque and redis-commands
ref #1575

* replace `new Buffer` (deprecated) with `Buffer.from`

* Buffer.from(0) should be Buffer.alloc(0)

.github/workflows/benchmark.yml

@@ -9,8 +9,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        node-version: [8.x, 10.x, 12.x]
-        redis-version: [5]
+        node-version: [10.x, 12.x, 14.x, 15.x]
+        redis-version: [5.x, 6.x]
 
     steps:
       - uses: actions/checkout@v2.3.4

.github/workflows/tests.yml

@@ -9,8 +9,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        node-version: [6.x, 8.x, 10.x, 12.x]
-        redis-version: [4.x, 5.x]
+        node-version: [10.x, 12.x, 14.x, 15.x]
+        redis-version: [4.x, 5.x, 6.x]
 
     steps:
       - uses: actions/checkout@v2.3.4

.github/workflows/tests_windows.yml

@@ -9,7 +9,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        node-version: [6.x, 8.x, 10.x, 12.x]
+        node-version: [10.x, 12.x, 14.x, 15.x]
     steps:
       - uses: actions/checkout@v2.3.4
         with: