Re-expose webrender debugger feature in components/servo

Update ws in debugger to 0.7.3 Update lockfile
servo · bors-servo · Mar 19, 2018 · Mar 18, 2018 · Mar 20, 2018 · 4dadfd02078116fe97e2cebcc92568ea37b0a617
commit 4dadfd02078116fe97e2cebcc92568ea37b0a617
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/components/debugger/Cargo.toml b/components/debugger/Cargo.toml
@@ -12,4 +12,4 @@ crate_type = ["rlib"]
 
 [dependencies]
 log = "0.3.5"
-ws = "0.6"
+ws = "0.7.3"
diff --git a/components/servo/Cargo.toml b/components/servo/Cargo.toml
@@ -17,6 +17,7 @@ webdriver = ["webdriver_server"]
 energy-profiling = ["profile_traits/energy-profiling"]
 debugmozjs = ["script/debugmozjs"]
 googlevr = ["webvr/googlevr"]
+webrender_debugger = ["webrender/debugger"]
 oculusvr = ["webvr/oculusvr"]
 unstable = [
     "euclid/unstable",