Fix: dev dependencies

 * add phpunit (stable)
 * add .lock for predictable results

Author: till

.gitignore

@@ -6,7 +6,6 @@
 .*.sw*
 .*.un~
 build/
-composer.lock
 nbproject
 tmp/
 vendor/

composer.json

@@ -24,7 +24,8 @@
         "guzzle/http"                : "3.*",
         "guzzle/plugin-mock"         : "3.*",
         "videlalvaro/php-amqplib"    : "2.*",
-        "predis/predis"              : "0.8.*"
+        "predis/predis"              : "0.8.*",
+        "phpunit/phpunit"            : "4.7.*"
     },
     "suggest" : {
         "ext-bcmath" : "Required by Check\\CpuPerformance",