Get at least dtrace-provider 0.3.1 for optionalDependencies

...to get a fix for install with decoupled npm (e.g. with homebrew's
node and npm).

Fixes #178 #181.

CHANGES.md

@@ -8,7 +8,9 @@ Known issues:
 
 ## bunyan 1.2.1 (not yet released)
 
-(nothing yet)
+- [issue #178, #181] Get at least dtrace-provider 0.3.1 for
+  optionalDependencies to get a fix for install with decoupled npm (e.g. with
+  homebrew's node and npm).
 
 
 ## bunyan 1.2.0

package.json

@@ -18,7 +18,7 @@
   "// comment1": "'dtrace-provider' required for dtrace features",
   "// comment2": "'mv' required for RotatingFileStream",
   "optionalDependencies": {
-    "dtrace-provider": "0.3.0",
+    "dtrace-provider": "~0.3 >0.3.0",
     "mv": "~2"
   },
   "devDependencies": {