more strict integer checks

ext/NilClass.rb

@@ -6,4 +6,8 @@ class NilClass
   def blank?
     true
   end
+
+  def not_an_integer?
+    true
+  end
 end

ext/numeric.rb

@@ -76,4 +76,8 @@ class Numeric
   def to_space_pretty
     to_bytes_pretty
   end
+
+  def not_an_integer?
+    !self.integer?
+  end
 end

ext/string.rb

@@ -16,4 +16,11 @@ class String
     return true if self == ''
     false
   end
+
+  def not_an_integer?
+    Integer(self)
+    false
+  rescue ArgumentError
+    true
+  end
 end