Add gemspec

rubella.gemspec

@@ -0,0 +1,16 @@
+Gem::Specification.new do |s|
+  s.name        = 'rubella'
+  s.version     = '0.1.0'
+  s.date        = '2015-05-05'
+  s.summary     = "Library to generate heatmaps"
+  s.description = "Rubella is a library to generate heatmaps to monitor visualize measured values
+easier. Like the load of multiple CPU cores over time."
+  s.authors     = ["Stormwind"]
+  s.email       = 'rebecca@quantenteilchen.de'
+  s.files       = `git ls-files`.split("\n")
+  s.test_files  = `git ls-files -- {test,spec,features}/*`.split("\n")
+  s.require_paths = %w(lib)
+  s.homepage    = 'https://github.com/Stormwind/rubella'
+  s.license     = '3-clause BSD'
+  s.extra_rdoc_files = %w(README.md)
+end