Upgrade GitHub CI runner from ubuntu-18.04 to ubuntu-20.04 (#136)

Signed-off-by: 守辰 <shouchen.zz@alibaba-inc.com>

.github/workflows/ci.yaml

@@ -16,7 +16,7 @@ env:
 jobs:
 
   golangci-lint:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - name: Checkout
         uses: actions/checkout@v2
@@ -42,7 +42,7 @@ jobs:
           args: --verbose
 
   unit-tests:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
         with:

.github/workflows/e2e-advanced-deployment-1.19.yaml

@@ -17,7 +17,7 @@ env:
 jobs:
 
   rollout:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
         with:

.github/workflows/e2e-advanced-deployment-1.23.yaml

@@ -17,7 +17,7 @@ env:
 jobs:
 
   rollout:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
         with:

.github/workflows/e2e-cloneset-1.19.yaml

@@ -17,7 +17,7 @@ env:
 jobs:
 
   rollout:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
         with:

.github/workflows/e2e-cloneset-1.23.yaml

@@ -17,7 +17,7 @@ env:
 jobs:
 
   rollout:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
         with:

.github/workflows/e2e-deployment-1.19.yaml

@@ -17,7 +17,7 @@ env:
 jobs:
 
   rollout:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
         with:

.github/workflows/e2e-deployment-1.23.yaml

@@ -17,7 +17,7 @@ env:
 jobs:
 
   rollout:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
         with:

.github/workflows/e2e-gateway.yaml

@@ -17,7 +17,7 @@ env:
 jobs:
 
   rollout:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
         with:

.github/workflows/e2e-others-1.19.yaml

@@ -17,7 +17,7 @@ env:
 jobs:
 
   rollout:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
         with:

.github/workflows/e2e-others-1.23.yaml

@@ -17,7 +17,7 @@ env:
 jobs:
 
   rollout:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
         with:

.github/workflows/e2e-statefulset-1.19.yaml

@@ -17,7 +17,7 @@ env:
 jobs:
 
   rollout:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
         with:

.github/workflows/e2e-statefulset-1.23.yaml

@@ -17,7 +17,7 @@ env:
 jobs:
 
   rollout:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
         with: