Update go to 1.14 (prometheus#1692)

Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>

Author: Julien Pivotto

.circleci/config.yml

@@ -9,7 +9,7 @@ executors:
   # also be updated.
   golang:
     docker:
-    - image: circleci/golang:1.13
+    - image: circleci/golang:1.14
 
 jobs:
   test:

.promu.yml

@@ -1,7 +1,7 @@
 go:
-    # Whenever the Go version is updated here, .travis.yml and
-    # .circle/config.yml should also be updated.
-    version: 1.13
+    # Whenever the Go version is updated here, .circle/config.yml should
+    # also be updated.
+    version: 1.14
 repository:
     path: github.com/prometheus/node_exporter
 build: