chore: use only go mod native version (#52)

* chore: use only go mod native version

* chore: new go versions

* update go version in go.mod

Co-authored-by: Livio Amstutz <livio.a@gmail.com>

.github/workflows/release.yml

@@ -5,7 +5,7 @@ jobs:
     runs-on: ubuntu-18.04
     strategy:
       matrix:
-        go: ['1.11', '1.12', '1.13', '1.14']
+        go: ['1.14', '1.15']
     name: Go ${{ matrix.go }} test
     steps:
       - uses: actions/checkout@v2

README.md

@@ -39,11 +39,9 @@ For your convinience you can find the relevant standards linked below.
 
 | Version | Supported          |
 |---------|--------------------|
-| <1.11   | :x:                |
-| 1.11    | :white_check_mark: |
-| 1.12    | :white_check_mark: |
-| 1.13    | :white_check_mark: |
+| <1.13   | :x:                |
 | 1.14    | :white_check_mark: |
+| 1.15    | :white_check_mark: |
 
 ## Why another library
 

go.mod

@@ -1,6 +1,6 @@
 module github.com/caos/oidc
 
-go 1.13
+go 1.15
 
 require (
 	github.com/caos/logging v0.0.0-20191210002624-b3260f690a6a