Fixed #432: Issue with new net/http/httptrace std lib package

dependency/resolver.go

diff --git a/dependency/resolver.go b/dependency/resolver.go
index e97ddd6..92e10cb 100644
--- a/dependency/resolver.go
+++ b/dependency/resolver.go
@@ -894,10 +894,11 @@
 		// https://blog.golang.org/the-app-engine-sdk-and-workspaces-gopath
 		info.Loc = LocAppengine
 		r.findCache[name] = info
-	} else if name == "context" {
-		// context is a package being added to the Go 1.7 standard library. Some
-		// packages, such as golang.org/x/net are importing it with build flags
-		// in files for go1.7. Need to detect this and handle it.
+	} else if name == "context" || name == "net/http/httptrace" {
+		// context and net/http/httptrace are packages being added to
+		// the Go 1.7 standard library. Some packages, such as golang.org/x/net
+		// are importing it with build flags in files for go1.7. Need to detect
+		// this and handle it.
 		info.Loc = LocGoroot
 		r.findCache[name] = info
 	}

tree/tree.go

diff --git a/tree/tree.go b/tree/tree.go
index 1d9def2..5b19336 100644
--- a/tree/tree.go
+++ b/tree/tree.go
@@ -172,10 +172,11 @@
 		// where Google products are playing with each other.
 		// https://blog.golang.org/the-app-engine-sdk-and-workspaces-gopath
 		info.Loc = dependency.LocAppengine
-	} else if name == "context" {
-		// context is a package being added to the Go 1.7 standard library. Some
-		// packages, such as golang.org/x/net are importing it with build flags
-		// in files for go1.7. Need to detect this and handle it.
+	} else if name == "context" || name == "net/http/httptrace" {
+		// context and net/http/httptrace are packages being added to
+		// the Go 1.7 standard library. Some packages, such as golang.org/x/net
+		// are importing it with build flags in files for go1.7. Need to detect
+		// this and handle it.
 		info.Loc = dependency.LocGoroot
 	}