Add golangci-lint config

Check in a .golangci.yml so the repo has a consistent linter setup.
Uses the v2 config format with the standard linter set plus bodyclose,
errorlint, gocritic, gosec, misspell, noctx, and prealloc.

Closes #561

Author: JamieMagee

.golangci.yml

@@ -0,0 +1,15 @@
+version: "2"
+
+linters:
+  default: standard
+  enable:
+    - bodyclose
+    - errorlint
+    - gocritic
+    - gosec
+    - misspell
+    - noctx
+    - prealloc
+
+issues:
+  max-same-issues: 0