[direnv] Add basic .envrc.example

.envrc.example

@@ -0,0 +1,9 @@
+toplevel="$(git rev-parse --show-toplevel)"
+
+# build and use the managed go sdk
+unset GOROOT
+make -C "$toplevel" go-check
+go_bin_path="$(make --no-print-directory -C $toplevel go-bin-path)"
+PATH="$go_bin_path:$PATH"
+
+# add custom direnv initialization below here

.gitignore

@@ -1,6 +1,7 @@
 .build
 .cache
 .data
+.envrc
 .glide
 .tmp
 .DS_Store

CONTRIBUTING.md

@@ -233,6 +233,16 @@ implementation can easily serve the needs for an entire suite of tests and
 the behavior is in a centralized location when it needs to be updated. Fakes
 are also less inclined to be impacted by changes to usage patterns.
 
+## Example [direnv][direnv_link] .envrc
+
+We have committed a basic `.envrc.example`. If you use [direnv][direnv_link],
+copy it into `.envrc`, edit as desired, and enable it with `direnv allow`. The
+`.envrc` is `.gitignored`. Be aware that [source_env][source_env] is insecure
+so keep your customizations in `.envrc`.
+
+[direnv_link]: https://direnv.net/
+[source_env]: https://direnv.net/man/direnv-stdlib.1.html#codesourceenv-ltfileordirpathgtcode
+
 ## Git hooks
 
 We have checked in a pre-commit hook which enforces `go fmt` styling. Please install it