build system: enable a build with sanitizers

[kewde]

The security of node-sqlite3 is a primary concern for all of us.
But our CI doesn't test for potential security issues, therefore I suggest the following improvements:

• binding-sanitizer.gyp: an additional .gyp file which is based on binding.gyp but adds additional flags to enable ASan, UBSan, TSan, etc..
• additional travis job that runs valgrind on the above builds using the test suite.

pinging potential persons of interest @jschlight @mohd-akram

[kewde]

This would perhaps catch #1323