Remove all duplication the specs

S3 and Swift now run the same specs. The only difference is the before
block that defines the stubbed HTTP requests and the responses from the
Swift and S3 servers

Gemfile.lock

@@ -6,12 +6,17 @@ GEM
       i18n (>= 0.7, < 2)
       minitest (~> 5.1)
       tzinfo (~> 1.1)
+    addressable (2.5.2)
+      public_suffix (>= 2.0.2, < 4.0)
     backports (3.11.2)
     concurrent-ruby (1.0.5)
+    crack (0.4.3)
+      safe_yaml (~> 1.0.0)
     domain_name (0.5.20170404)
       unf (>= 0.0.5, < 1.0.0)
     faraday (0.14.0)
       multipart-post (>= 1.2, < 3)
+    hashdiff (0.3.7)
     http-accept (1.7.0)
     http-cookie (1.0.3)
       domain_name (~> 0.5)
@@ -31,6 +36,7 @@ GEM
     multipart-post (2.0.0)
     mustermann (1.0.2)
     netrc (0.11.0)
+    public_suffix (3.0.2)
     purdytest (2.0.0)
       minitest (~> 5.5)
     rack (2.0.4)
@@ -50,6 +56,7 @@ GEM
       http-cookie (>= 1.0.2, < 2.0)
       mime-types (>= 1.16, < 4.0)
       netrc (~> 0.8)
+    safe_yaml (1.0.4)
     sentry-raven (2.7.2)
       faraday (>= 0.7.6, < 1.0)
     sinatra (2.0.1)
@@ -74,6 +81,10 @@ GEM
     unicorn (5.4.0)
       kgio (~> 2.6)
       raindrops (~> 0.7)
+    webmock (3.3.0)
+      addressable (>= 2.3.6)
+      crack (>= 0.3.2)
+      hashdiff
 
 PLATFORMS
   ruby
@@ -92,6 +103,7 @@ DEPENDENCIES
   sentry-raven
   sinatra
   sinatra-contrib
+  webmock
 
 BUNDLED WITH
    1.16.0