Sync build system and CI scripts with ndn-cxx

 * Update build flags
 * Update waf to version 2.0.21
 * Replace Travis CI with GitHub Actions

Change-Id: If45c45c7b9ed748ffd1c4e792075f6bb6f09462f
diff --git a/.gitignore b/.gitignore
index 608c272..8850587 100644
--- a/.gitignore
+++ b/.gitignore
@@ -26,4 +26,4 @@
 *.py[cod]
 
 # Other
-/VERSION
+/VERSION.info