[CI] Add definition for 5.4 docker images, update README

Author: Mordil

.gitlab/ci/centos-7.yml

@@ -16,10 +16,9 @@ swift trunk:
   image: swiftlang/swift:nightly-master-centos7
   allow_failure: true
 
-# 5.4 nightlies are not available yet
-# swift 5.4:
-#   extends: .centos7
-#   image: swiftlang/swift:nightly-5.4-centos7
+swift 5.4:
+  extends: .centos7
+  image: swiftlang/swift:nightly-5.4-centos7
 
 swift 5.3:
   extends: .centos7

.gitlab/ci/platform-test.yml

@@ -29,10 +29,9 @@ swift trunk:
   image: swiftlang/swift:nightly-master-${SWIFT_PLATFORM_NAME}
   allow_failure: true
 
-# 5.4 nightlies are not available yet
-# swift 5.4:
-#   extends: .standard-platform
-#   image: swiftlang/swift:nightly-5.4-${SWIFT_PLATFORM_NAME}
+swift 5.4:
+  extends: .standard-platform
+  image: swiftlang/swift:nightly-5.4-${SWIFT_PLATFORM_NAME}
 
 swift 5.3:
   extends: .standard-platform

README.md

@@ -120,13 +120,13 @@ receive regular unit testing (either in development, or with CI) against the **c
 
 | Platform              | Swift 5.2          | 5.3                | 5.4                | Trunk              |
 |:----------------------|:------------------:|:------------------:|:------------------:|:------------------:|
-| macOS Latest (Intel)  |                    | :white_check_mark: |                    |                    |
+| macOS Latest (Intel)  |                    |                    | :white_check_mark: |                    |
 | Ubuntu 20.04 (Focal)  | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: |
 | Ubuntu 18.04 (Bionic) | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: |
 | Ubuntu 16.04 (Xenial) | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: |
 | Amazon Linux 2        | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: |
-| CentOS 7              | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: |
 | CentOS 8              | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: |
+| CentOS 7              | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: |
 
 For older versions of **RediStack**, view each summary below.
 
@@ -135,7 +135,7 @@ For older versions of **RediStack**, view each summary below.
 
 | Platform              | Swift 5.1          | 5.2                | 5.3                |
 |:----------------------|:------------------:|:------------------:|:------------------:|
-| macOS Latest (Intel)  |                    |                    | :white_check_mark: |
+| macOS Latest (Intel)  |                    |                    |                    |
 | Ubuntu 20.04 (Focal)  |                    | :white_check_mark: | :white_check_mark: |
 | Ubuntu 18.04 (Bionic) | :white_check_mark: | :white_check_mark: | :white_check_mark: |
 | Ubuntu 16.04 (Xenial) | :white_check_mark: | :white_check_mark: | :white_check_mark: |