Bump Golang 1.15.5

Changes: https://golang.org/doc/devel/release.html#go1.15

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

.github/workflows/ci.yml

@@ -20,7 +20,7 @@ jobs:
 
     strategy:
       matrix:
-        go-version: [1.15.2]
+        go-version: [1.15.5]
         os: [ubuntu-18.04, macos-10.15, windows-2019]
 
     steps:
@@ -73,7 +73,7 @@ jobs:
     steps:
       - uses: actions/setup-go@v1
         with:
-          go-version: '1.15.2'
+          go-version: '1.15.5'
 
       - uses: actions/checkout@v2
         with:
@@ -106,7 +106,7 @@ jobs:
     steps:
       - uses: actions/setup-go@v1
         with:
-          go-version: '1.15.2'
+          go-version: '1.15.5'
 
       - name: Set env
         shell: bash
@@ -139,7 +139,7 @@ jobs:
     steps:
       - uses: actions/setup-go@v1
         with:
-          go-version: '1.15.2'
+          go-version: '1.15.5'
 
       - name: Set env
         shell: bash
@@ -174,7 +174,7 @@ jobs:
     steps:
       - uses: actions/setup-go@v1
         with:
-          go-version: '1.15.2'
+          go-version: '1.15.5'
 
       - uses: actions/checkout@v2
         with:
@@ -236,7 +236,7 @@ jobs:
     steps:
       - uses: actions/setup-go@v1
         with:
-          go-version: '1.15.2'
+          go-version: '1.15.5'
 
       - uses: actions/checkout@v2
         with:

.github/workflows/nightly.yml

@@ -18,7 +18,7 @@ jobs:
     steps:
       - uses: actions/setup-go@v1
         with:
-          go-version: '1.15.2'
+          go-version: '1.15.5'
 
       - uses: actions/checkout@v2
         with:
@@ -131,7 +131,7 @@ jobs:
     steps:
       - uses: actions/setup-go@v1
         with:
-          go-version: '1.15.2'
+          go-version: '1.15.5'
 
       - uses: actions/checkout@v2
         with:

.github/workflows/release.yml

@@ -62,7 +62,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v1
         with:
-          go-version: '1.15.2'
+          go-version: '1.15.5'
 
       - name: Set env
         shell: bash