Alter gemspec so we don't depend on exact version of httparty

Means the library plays nicer in projects.

Gemfile.lock

@@ -1,37 +1,38 @@
 PATH
   remote: .
   specs:
-    neography (0.0.20)
-      crack (= 0.1.8)
-      httparty (= 0.8.1)
+    neography (0.0.26)
+      httparty (>= 0.8.1)
       json
+      oj
       os
       rake (>= 0.8.7)
       rubyzip
 
 GEM
   remote: http://rubygems.org/
   specs:
-    crack (0.1.8)
     diff-lcs (1.1.3)
-    httparty (0.8.1)
-      multi_json
+    httparty (0.8.3)
+      multi_json (~> 1.0)
       multi_xml
-    json (1.6.4)
-    multi_json (1.0.4)
-    multi_xml (0.4.1)
+    json (1.7.3)
+    json (1.7.3-java)
+    multi_json (1.3.6)
+    multi_xml (0.5.1)
     net-http-spy (0.2.1)
-    os (0.9.5)
+    oj (1.2.9)
+    os (0.9.6)
     rake (0.8.7)
-    rspec (2.7.0)
-      rspec-core (~> 2.7.0)
-      rspec-expectations (~> 2.7.0)
-      rspec-mocks (~> 2.7.0)
-    rspec-core (2.7.1)
-    rspec-expectations (2.7.0)
-      diff-lcs (~> 1.1.2)
-    rspec-mocks (2.7.0)
-    rubyzip (0.9.5)
+    rspec (2.10.0)
+      rspec-core (~> 2.10.0)
+      rspec-expectations (~> 2.10.0)
+      rspec-mocks (~> 2.10.0)
+    rspec-core (2.10.1)
+    rspec-expectations (2.10.0)
+      diff-lcs (~> 1.1.3)
+    rspec-mocks (2.10.1)
+    rubyzip (0.9.8)
 
 PLATFORMS
   java

neography.gemspec

@@ -22,7 +22,7 @@ Gem::Specification.new do |s|
   s.add_development_dependency "rspec"
   s.add_development_dependency "net-http-spy", "0.2.1"
   s.add_development_dependency "rake", "~> 0.8.7"
-  s.add_dependency "httparty", "0.8.1"
+  s.add_dependency "httparty", ">= 0.8.1"
   s.add_dependency "rake", ">= 0.8.7"
   s.add_dependency "json"
   s.add_dependency "os"