1.1.6-20180301145320Z-23eb1ae97424cbc4cfaaaee23873c4a305d13603

Update simplesamlphp SAML2 library

Updates saml2 to 1.10.5.

Resolves security advisory SA-201802-01

Note: version 1.1.5 of Stepup-tiqr did not use a tagged version of
saml2, but commit ec7e645. This commit is almost identical to version
v1.6.1/v0.7.1 of saml2.