Update comments

- updates comments and adds where missing
- updates locks so that unlock is done via defer instead of
at the end of the statement
- extracts timeout variable in two places
- remove makeClient() unused method from metrics package

No-harm changes tested via go build.

Signed-off-by: Alex Ellis (VMware) <alexellis2@gmail.com>

gateway/handlers/forwarding_proxy.go

@@ -23,7 +23,7 @@ import (
 // functionMatcher parses out the service name (group 1) and rest of path (group 2).
 var functionMatcher = regexp.MustCompile("^/?(?:async-)?function/([^/?]+)([^?]*)")
 
-// Indicies and meta-data for functionMatcher regex parts
+// Indices and meta-data for functionMatcher regex parts
 const (
 	hasPathCount = 3
 	routeIndex   = 0 // routeIndex corresponds to /function/ or /async-function/