Remove ruby 2.5 support

Author: cjmartian

.github/workflows/main.yml

@@ -11,7 +11,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby-version: ["2.5", "2.6"]
+        ruby-version: ["2.6"]
     steps:
       - name: Checkout code
         uses: actions/checkout@v1
@@ -30,7 +30,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby-version: ["2.5", "2.6"]
+        ruby-version: ["2.6"]
     steps:
       - name: Checkout code
         uses: actions/checkout@v1
@@ -49,7 +49,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby-version: ["2.5", "2.6"]
+        ruby-version: ["2.6"]
     steps:
       - name: Checkout code
         uses: actions/checkout@v1
@@ -75,8 +75,7 @@ jobs:
       fail-fast: false
       matrix:
         # 2.7 and 3.0 fail at the moment
-        # ruby-version: ["2.5", "2.6", "2.7", "3.0"]
-        ruby-version: ["2.5", "2.6"]
+        ruby-version: ["2.6"]
     steps:
       - name: Checkout code
         uses: actions/checkout@v1