Add pear modules, mail and net_smtp via composer (#93)

Add pear modules, mail and net_smtp via composer, remove php 5.6 build due to phpunit 6

lib/composer/vendor/pear/mail/tests/Makefile

@@ -0,0 +1,8 @@
+
+clean:
+	rm -f *.log *.php *.diff *.exp *.out
+
+
+
+test:
+	cd .. && pear run-tests tests/*.phpt && cd tests;