Be less specific on faraday-http-cache gem version

Author: mikekr1

ldclient-rb.gemspec

@@ -25,7 +25,7 @@ Gem::Specification.new do |spec|
 
   spec.add_runtime_dependency "json", "~> 1.8"
   spec.add_runtime_dependency "faraday", "~> 0.9"
-  spec.add_runtime_dependency "faraday-http-cache", "= 1.3.0"
+  spec.add_runtime_dependency "faraday-http-cache", "~> 1.3.0"
   spec.add_runtime_dependency "thread_safe", "~> 0.3"
   spec.add_runtime_dependency "net-http-persistent", "~> 2.9"
   spec.add_runtime_dependency "concurrent-ruby", "~> 1.0.0"