fix formatting issues

spec/mapping_spec.cr

@@ -4,14 +4,14 @@ require "base64"
 class SimpleMapping
   DB.mapping({
     c0: Int32,
-    c1: String
+    c1: String,
   })
 end
 
 class NonStrictMapping
   DB.mapping({
     c1: Int32,
-    c2: String
+    c2: String,
   }, strict: false)
 end
 
@@ -37,7 +37,6 @@ class MappingWithKeys
 end
 
 class MappingWithConverter
-
   module Base64Converter
     def self.from_rs(rs)
       Base64.decode(rs.read(String))
@@ -69,7 +68,6 @@ macro expect_mapping(query, t, values)
 end
 
 describe "DB.mapping" do
-
   it "should initialize a simple mapping" do
     expect_mapping("1,a", SimpleMapping, {c0: 1, c1: "a"})
   end
@@ -149,5 +147,4 @@ describe "DB.mapping" do
       objs[1].c1.should eq("b")
     end
   end
-
 end

src/db/error.cr

@@ -1,9 +1,7 @@
 module DB
-
   class Error < Exception
   end
 
   class MappingException < Exception
   end
-  
 end

src/db/mapping.cr

@@ -1,5 +1,4 @@
 module DB
-
   # Empty module used for marking a class as supporting DB:Mapping
   module Mappable; end