ci: add Go1.11, drop Go1.8 (#17)

Author: sbinet

.travis.yml

@@ -13,13 +13,13 @@ matrix:
  allow_failures:
    - go: master
  include:
-   - go: 1.8.x
-     env:
-       - TAGS="-tags travis"
    - go: 1.9.x
      env:
        - TAGS="-tags travis"
    - go: 1.10.x
+     env:
+       - TAGS="-tags travis"
+   - go: 1.11.x
      env:
        - TAGS="-tags travis"
        - COVERAGE="-cover"

appveyor.yml

@@ -12,7 +12,7 @@ environment:
   matrix:
     - TARGET: x86_64-pc-windows-gnu
 
-stack: go 1.10
+stack: go 1.11
 
 build_script:
   - go get -v -t -race ./...