Fixed error messages when calling rake

I got lots of error messages when calling rake:

    $ rake -T
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/version.rb:2: warning: already initialized constant VERSION
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/version.rb:5: warning: already initialized constant MAJOR
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/version.rb:5: warning: already initialized constant MINOR
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/version.rb:5: warning: already initialized constant BUILD
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/version.rb:6: warning: already initialized constant NUMBERS
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake.rb:27: warning: already initialized constant RAKEVERSION
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/early_time.rb:17: warning: already initialized constant EARLY
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/alt_system.rb:32: warning: already initialized constant WINDOWS
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/application.rb:31: warning: already initialized constant DEFAULT_RAKEFILES
    WARNING: Possible conflict with Rake extension: String#ext already exists
    WARNING: Possible conflict with Rake extension: String#pathmap already exists
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/task_arguments.rb:77: warning: already initialized constant EMPTY_TASK_ARGS
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/invocation_chain.rb:49: warning: already initialized constant EMPTY
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/file_utils.rb:9: warning: already initialized constant RUBY
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/file_utils.rb:86: warning: already initialized constant LN_SUPPORTED
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/file_utils_ext.rb:16: warning: already initialized constant DEFAULT
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/dsl_definition.rb:150: warning: already initialized constant DeprecatedCommands
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/file_list.rb:44: warning: already initialized constant ARRAY_METHODS
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/file_list.rb:47: warning: already initialized constant MUST_DEFINE
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/file_list.rb:51: warning: already initialized constant MUST_NOT_DEFINE
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/file_list.rb:55: warning: already initialized constant SPECIAL_RETURN
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/file_list.rb:61: warning: already initialized constant DELEGATING_METHODS
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/file_list.rb:364: warning: already initialized constant DEFAULT_IGNORE_PATTERNS
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake/file_list.rb:370: warning: already initialized constant DEFAULT_IGNORE_PROCS
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake.rb:68: warning: already initialized constant FileList
    /home/igel/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/rake.rb:69: warning: already initialized constant RakeFileUtils
    *****************************************************************
    DEPRECATION WARNING: you are using a deprecated constant that will
    be removed from a future version of RSpec.
    
    /home/igel/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/rake_module.rb:25:in `load'
    
    * Rspec is deprecated.
    * RSpec is the new top-level module in RSpec-2
    *****************************************************************

Also:

- Upgraded rspec to 2.10.0
- Mapped the default rake task to spec