fix rubocop Style/LineEndConcatenation cop

.rubocop_rubyzip.yml

@@ -170,11 +170,6 @@ Style/Lambda:
 Style/LeadingCommentSpace:
   Enabled: false
 
-# Offense count: 9
-# Cop supports --auto-correct.
-Style/LineEndConcatenation:
-  Enabled: false
-
 # Offense count: 7
 # Cop supports --auto-correct.
 Style/MethodCallParentheses:

lib/zip/entry.rb

@@ -514,7 +514,7 @@ module Zip
                when 'file'
                  if name_is_directory?
                    raise ArgumentError,
-                         "entry name '#{newEntry}' indicates directory entry, but " +
+                         "entry name '#{newEntry}' indicates directory entry, but " \
                              "'#{src_path}' is not a directory"
                  end
                  :file
@@ -524,7 +524,7 @@ module Zip
                when 'link'
                  if name_is_directory?
                    raise ArgumentError,
-                         "entry name '#{newEntry}' indicates directory entry, but " +
+                         "entry name '#{newEntry}' indicates directory entry, but " \
                              "'#{src_path}' is not a directory"
                  end
                  :symlink
@@ -597,7 +597,7 @@ module Zip
           ::FileUtils.rm_f dest_path
         else
           raise ::Zip::DestinationFileExistsError,
-                "Cannot create directory '#{dest_path}'. " +
+                "Cannot create directory '#{dest_path}'. " \
                     'A file already exists with that name'
         end
       end
@@ -622,12 +622,12 @@ module Zip
             return
           else
             raise ::Zip::DestinationFileExistsError,
-                  "Cannot create symlink '#{dest_path}'. " +
+                  "Cannot create symlink '#{dest_path}'. " \
                       'A symlink already exists with that name'
           end
         else
           raise ::Zip::DestinationFileExistsError,
-                "Cannot create symlink '#{dest_path}'. " +
+                "Cannot create symlink '#{dest_path}'. " \
                     'A file already exists with that name'
         end
       end

lib/zip/file.rb

@@ -379,7 +379,7 @@ module Zip
       srcPathIsDirectory = ::File.directory?(srcPath)
       if newEntry.is_directory && !srcPathIsDirectory
         raise ArgumentError,
-              "entry name '#{newEntry}' indicates directory entry, but " +
+              "entry name '#{newEntry}' indicates directory entry, but " \
                   "'#{srcPath}' is not a directory"
       elsif !newEntry.is_directory && srcPathIsDirectory
         newEntry.name += '/'

lib/zip/input_stream.rb

@@ -132,7 +132,7 @@ module Zip
         && @current_entry.compressed_size == 0 \
         && @current_entry.size == 0
         raise GPFBit3Error,
-              'General purpose flag Bit 3 is set so not possible to get proper info from local header.' + \
+              'General purpose flag Bit 3 is set so not possible to get proper info from local header.' \
               'Please use ::Zip::File instead of ::Zip::InputStream'
       end
       @decompressor  = get_decompressor

test/gentestfiles.rb

@@ -108,8 +108,8 @@ class TestZipFile
     # http://stahlworks.com/dev/index.php?tool=zipunzip
     # that works with the above code
     raise $!.to_s +
-              "\n\nziptest.rb requires the Info-ZIP program 'zip' in the path\n" +
+              "\n\nziptest.rb requires the Info-ZIP program 'zip' in the path\n" \
-              "to create test data. If you don't have it you can download\n" +
+              "to create test data. If you don't have it you can download\n" \
               'the necessary test files at http://sf.net/projects/rubyzip.'
   end