Add tasks - close #139

build_tests/cfile/Rsconscript

@@ -1,4 +1,4 @@
-build do
+default do
   Environment.new do |env|
     env.CFile("lexer.c", "lexer.l")
     env.CFile("parser.c", "parser.y")

build_tests/cfile/error_unknown_extension.rb

@@ -1,4 +1,4 @@
-build do
+default do
   Environment.new do |env|
     env.CFile("file.c", "foo.bar")
   end