panic: interface conversion: interface {} is map[string]interface {}, not string
    goroutine 138 [running]:
    <http://github.com/pulumi/pulumi-aws/vendor/github.com/jen20/awspolicyequivalence.newAWSStringSet(0x28a5f80|github.com/pulumi/pulumi-aws/vendor/github.com/jen20/awspolicyequivalence.newAWSStringSet(0x28a5f80>, 0xc420615a60, 0xc420615e00, 0x2, 0x2)
    	/home/travis/gopath/src/github.com/pulumi/pulumi-aws/vendor/github.com/jen20/awspolicyequivalence/aws_policy_equivalence.go:386 +0x328
    <http://github.com/pulumi/pulumi-aws/vendor/github.com/jen20/awspolicyequivalence.(*awsPolicyStatement).equals(0xc420959c20|github.com/pulumi/pulumi-aws/vendor/github.com/jen20/awspolicyequivalence.(*awsPolicyStatement).equals(0xc420959c20>, 0xc420959cb0, 0x0)
    	/home/travis/gopath/src/github.com/pulumi/pulumi-aws/vendor/github.com/jen20/awspolicyequivalence/aws_policy_equivalence.go:176 +0x2e1
    <http://github.com/pulumi/pulumi-aws/vendor/github.com/jen20/awspolicyequivalence.(*awsPolicyDocument).equals(0xc420724a00|github.com/pulumi/pulumi-aws/vendor/github.com/jen20/awspolicyequivalence.(*awsPolicyDocument).equals(0xc420724a00>, 0xc420724a80, 0x0)
    	/home/travis/gopath/src/github.com/pulumi/pulumi-aws/vendor/github.com/jen20/awspolicyequivalence/aws_policy_equivalence.go:114 +0x109
    <http://github.com/pulumi/pulumi-aws/vendor/github.com/jen20/awspolicyequivalence.PoliciesAreEquivalent(0xc4204f3000|github.com/pulumi/pulumi-aws/vendor/github.com/jen20/awspolicyequivalence.PoliciesAreEquivalent(0xc4204f3000>, 0xf3, 0xc4207b4410, 0xc8, 0xc420adee10, 0xc420adee08, 0xc420adedf8)