Correct header file name

Author: hlovdal

REFERENCE.md

@@ -97,7 +97,7 @@ unittest(your_test_name)
 unittest_main()
 ```
 
-This test defines one `unittest` (a macro provided by `ArduionUnitTests.h`), called `your_test_name`, which makes some assertions on the target library.  The `unittest_main()` is a macro for the `int main()` boilerplate required for unit testing.
+This test defines one `unittest` (a macro provided by `ArduinoUnitTests.h`), called `your_test_name`, which makes some assertions on the target library.  The `unittest_main()` is a macro for the `int main()` boilerplate required for unit testing.
 
 
 # Mocks

SampleProjects/DoSomething/README.md

@@ -101,7 +101,7 @@ unittest(your_test_name)
 unittest_main()
 ```
 
-This test defines one `unittest` (a macro provided by `ArduionUnitTests.h`), called `your_test_name`, which makes some assertions on the target library.  The `int main` section is boilerplate.
+This test defines one `unittest` (a macro provided by `ArduinoUnitTests.h`), called `your_test_name`, which makes some assertions on the target library.  The `int main` section is boilerplate.
 
 
 # Credits