update snapcraft go

Makefile

@@ -53,7 +53,7 @@ snap/clean:
 	rm -f cointop_*.snap
 
 snap/stage:
-	snapcraft stage
+	GO111MODULE=off snapcraft stage
 
 snap/build: snap/clean snap/stage
 	snapcraft snap

snapcraft.yaml

@@ -1,16 +1,16 @@
 name: cointop
 version: master
 version-script: git -C parts/cointop/build rev-parse --short HEAD
-summary: Interactive terminal based UI application for tracking cryptocurrencies 
+summary: Interactive terminal based UI application for tracking cryptocurrencies
 description: |
-  cointop is a fast and lightweight interactive terminal based UI application for tracking and monitoring cryptocurrency coin stats in real-time. 
+  cointop is a fast and lightweight interactive terminal based UI application for tracking and monitoring cryptocurrency coin stats in real-time.
 
 grade: stable
 confinement: strict
 
 parts:
   go:
-    source-tag: go1.10
+    source-tag: go1.11
   cointop:
     after: [go]
     source: .