docker: install Devel::CheckLib explicitly

Change-Id: Idcc751e116d37cf33097f5f1f42e4ae6552e3527
diff --git a/Dockerfile b/Dockerfile
index cb329c2..54720ef 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -49,6 +49,7 @@
 
 # Install dependencies
 RUN cpm install -g https://github.com/Akron/Mojolicious-Plugin-Localize.git && \
+    cpm install -g Devel::CheckLib && \
     cpm install -g
 
 # Build derekovecs