E2E tests use repeated strings for test data where constants add no value (#97)

---------

Co-authored-by: Pasha Sviderski <me@psviderski.name>
Co-authored-by: Anton Ovchinnikov <anton@tonyo.info>

.golangci.yaml

@@ -1,4 +1,10 @@
 version: "2"
+
+run:
+  concurrency: 4
+  tests: true
+  timeout: 5m
+
 linters:
   default: none
   enable:
@@ -23,8 +29,14 @@ linters:
     # - unparam
     # - unused
     - whitespace
+  exclusions:
+    rules:
+      - path: ^test/e2e
+        linters:
+          - goconst  # constants here add no value, so we skip goconst only for test/e2e.
 
 formatters:
   enable:
-    - gofmt
-    # - goimports
+    - gofumpt
+    - goimports
+