[CLOUD-319] Make mixlib-log an optional dependency

This change makes mixlib-log an optional dependency. When it's available
in the LOAD_PATH it will be used by default, otherwise, all logging will
will be forwarded to a null logger that does nothing. This is useful for
cases where small utilities can consume mixlib-authentication and not
have to pull in additional gems.

Signed-off-by: Ryan Cragun <me@ryan.ec>

1 files changed, 1 insertions, 0 deletions

diff --git a/Gemfile b/Gemfile
index 3297f71..25103b0 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,4 +3,5 @@ gemspec
 
 group(:development) do
   gem "pry"
+  gem "mixlib-log"
 end