Fix improper overrides of unittest compilers YAML section

Author: ianfixes

CHANGELOG.md

@@ -29,6 +29,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - OSX splash screen re-disabled
 - ArduinoCITable didn't initialize its size on `clear()`
 - CPP file aggregation now ignores dotfiles
+- Unit test `compilers` section of YAML configuration is now properly inherited from parent configuration files
 
 ### Security
 

SampleProjects/DoSomething/.arduino-ci.yaml

@@ -11,5 +11,3 @@ unittest:
     - uno
     - due
     - leonardo
-  compilers:
-    - g++

SampleProjects/TestSomething/.arduino-ci.yml

@@ -2,5 +2,3 @@ unittest:
   platforms:
     - uno
     - due
-  compilers:
-    - g++

lib/arduino_ci/ci_config.rb

@@ -126,12 +126,12 @@ def load_yaml(path)
 
       if yml.include?("compile")
         valid_data = validate_data("compile", yml["compile"], COMPILE_SCHEMA)
-        @compile_info = valid_data
+        valid_data.each { |k, v| @compile_info[k] = v }
       end
 
       if yml.include?("unittest")
         valid_data = validate_data("unittest", yml["unittest"], UNITTEST_SCHEMA)
-        @unittest_info = valid_data
+        valid_data.each { |k, v| @unittest_info[k] = v }
       end
 
       self

lib/arduino_ci/cpp_library.rb

@@ -60,17 +60,17 @@ def vendor_bundle?(path)
     # This requires compilation of a sample program, and will be cached
     # @param gcc_binary
     def libasan?(gcc_binary)
-      if @has_libasan_cache.nil?
+      unless @has_libasan_cache.key?(gcc_binary)
         file = Tempfile.new('arduino_ci_libasan_check')
         begin
           file.write "int main(){}"
           file.close
-          @has_libasan_cache = run_gcc(gcc_binary, "-o", "/dev/null", "-fsanitize=address", file.path)
+          @has_libasan_cache[gcc_binary] = run_gcc(gcc_binary, "-o", "/dev/null", "-fsanitize=address", file.path)
         ensure
           file.delete
         end
       end
-      @has_libasan_cache
+      @has_libasan_cache[gcc_binary]
     end
 
     # Get a list of all CPP source files in a directory and its subdirectories