Setting the idle_timeout_in_minutes value of the azurerm_public_ip
resource always caused a panic.
This fixes it and adds a test to actually test that particular
attribute.
Had to make some changes to this resource. Params were not being set in
the Read func - also added a statefunc to the IPAddressAllocation as
that was coming back in a different case to how we were sending it. We
need to treat that property as case-insensitive
```
% make testacc TEST=./builtin/providers/azurerm TESTARGS='-run=TestAccAzureRMPublicIpStatic_'
==> Checking that code complies with gofmt requirements...
go generate $(go list ./... | grep -v /terraform/vendor/)
TF_ACC=1 go test ./builtin/providers/azurerm -v
-run=TestAccAzureRMPublicIpStatic_ -timeout 120m
=== RUN TestAccAzureRMPublicIpStatic_importBasic
--- PASS: TestAccAzureRMPublicIpStatic_importBasic (128.06s)
=== RUN TestAccAzureRMPublicIpStatic_basic
--- PASS: TestAccAzureRMPublicIpStatic_basic (126.25s)
=== RUN TestAccAzureRMPublicIpStatic_withTags
--- PASS: TestAccAzureRMPublicIpStatic_withTags (145.99s)
=== RUN TestAccAzureRMPublicIpStatic_update
--- PASS: TestAccAzureRMPublicIpStatic_update (192.32s)
PASS
ok github.com/hashicorp/terraform/builtin/providers/azurerm
592.648s
```
Kristinn Örn Sigurðsson