Run tests with the race detector

At some point recently this was fixed (maybe investigate more and
figure out how/why this has been resolved?)

Add Go 1.10 to Travis CI.

.travis.yml

@@ -3,12 +3,14 @@ go_import_path: github.com/kevinburke/ssh_config
 language: go
 
 go:
-  - 1.7
-  - 1.8
-  - tip
+  - 1.7.x
+  - 1.8.x
+  - 1.9.x
+  - 1.10.x
+  - master
 
 before_script:
     - go get -u ./...
 
 script:
-    - make test
+    - make race-test

AUTHORS.txt

@@ -1,3 +1,4 @@
 Eugene Terentev <eugene@terentev.net>
 Kevin Burke <kev@inburke.com>
 Sergey Lukjanov <me@slukjanov.name>
+Wayne Ashley Berry <wayneashleyberry@gmail.com>

Makefile

@@ -13,7 +13,10 @@ lint: $(MEGACHECK)
 
 test: lint
 	@# the timeout helps guard against infinite recursion
-	go test -timeout=50ms ./...
+	go test -timeout=250ms ./...
+
+race-test: lint
+	go test -timeout=500ms -race ./...
 
 $(BUMP_VERSION):
 	go get -u github.com/Shyp/bump_version