added an overload for operator<< of the ContextBuilder that catches by const ref and use a static assert - relates #23

Added option to show duration of test case execution and added a timeout(seconds) decorator - marking them as failed if they exceed it - closes #68 - closes #67
diff --git a/examples/all_features/test_output/stringification.cpp.txt b/examples/all_features/test_output/stringification.cpp.txt
index 1305b3c..516cc9d 100644
--- a/examples/all_features/test_output/stringification.cpp.txt
+++ b/examples/all_features/test_output/stringification.cpp.txt
@@ -36,7 +36,7 @@
   5
 
 ===============================================================================
-[doctest] test cases:    2 |    0 passed |    2 failed | 
-[doctest] assertions:    4 |    0 passed |    4 failed |
+[doctest] test cases:      2 |      0 passed |      2 failed | 
+[doctest] assertions:      4 |      0 passed |      4 failed |
 [doctest] Status: FAILURE!
 Program code.