Bump elasticity version to 6.0.12 (close snowplow/snowplow#3249)

Gemfile

@@ -20,7 +20,7 @@ ruby "2.3.1"
 # built with Bundler, so we add in the
 # RubyGems it requires here.
 gem "contracts", "~> 0.9", "<= 0.11"
-gem "elasticity", "~> 6.0.11"
+gem "elasticity", "~> 6.0.12"
 gem "sluice", "~> 0.4.0"
 gem "awrence", "~> 0.1.0"
 gem "snowplow-tracker", "~> 0.5.2"

Gemfile.lock

@@ -17,8 +17,8 @@ GEM
     docile (1.1.5)
     domain_name (0.5.20170404)
       unf (>= 0.0.5, < 1.0.0)
-    elasticity (6.0.11)
-      fog (~> 1.0)
+    elasticity (6.0.12)
+      fog-aws (~> 1.0)
       rest-client (~> 1.0)
       unf (~> 0.1)
     excon (0.52.0)
@@ -39,6 +39,11 @@ GEM
       ipaddress (~> 0.5)
       nokogiri (~> 1.5, >= 1.5.11)
       opennebula
+    fog-aws (1.4.0)
+      fog-core (~> 1.38)
+      fog-json (~> 1.0)
+      fog-xml (~> 0.1)
+      ipaddress (~> 0.8)
     fog-brightbox (0.11.0)
       fog-core (~> 1.22)
       fog-json
@@ -151,7 +156,7 @@ DEPENDENCIES
   awrence (~> 0.1.0)
   contracts (~> 0.9, <= 0.11)
   coveralls
-  elasticity (~> 6.0.11)
+  elasticity (~> 6.0.12)
   iglu-ruby-client (>= 0.1.0)
   rspec (~> 2.14, >= 2.14.1)
   sluice (~> 0.4.0)
@@ -162,4 +167,4 @@ RUBY VERSION
    ruby 2.3.1p0 (jruby 9.1.6.0)
 
 BUNDLED WITH
-   1.14.6
+   1.15.1