Resolve "Improve security by enabling and enforcing more linting rules"

Description

See #242 (closed)

.golangci.yml

@@ -31,6 +31,12 @@ linters-settings:
         min-complexity: 15
     golint:
         min-confidence: 0.8
+    errcheck:
+        # Report about not checking of errors in type assertions: `a := b.(MyStruct)`.
+        # Such cases aren't reported by default.
+        # Default: false
+        check-type-assertions: true
+
 
 linters:
     # enable the specific needed linters
@@ -46,6 +52,7 @@ linters:
         - revive
         - whitespace
         - deadcode
+        - errcheck
 issues:
     exclude-use-default: false
     max-issues-per-linter: 0