gem update; version bump

Gemfile.lock

 PATH
   remote: .
   specs:
-    steem-ruby (0.9.2)
+    steem-ruby (0.9.3)
       bitcoin-ruby (~> 0.0, >= 0.0.18)
       ffi (~> 1.9, >= 1.9.23)
       hashie (~> 3.5, >= 3.5.7)
@@ -21,7 +21,7 @@ GEM
     docile (1.3.1)
     ffi (1.9.25)
     hashdiff (0.3.7)
-    hashie (3.5.7)
+    hashie (3.6.0)
     json (2.1.0)
     little-plugger (1.1.4)
     logging (2.2.2)
@@ -70,4 +70,4 @@ DEPENDENCIES
   yard (~> 0.9, >= 0.9.12)
 
 BUNDLED WITH
-   1.16.1
+   1.16.5

lib/steem/version.rb

 module Steem
-  VERSION = '0.9.2'
+  VERSION = '0.9.3'
   AGENT_ID = "steem-ruby/#{VERSION}"
 end