update scaleway-api SDK

[nicolai86]

prerequisite to implement https://github.com/terraform-providers/terraform-provider-scaleway/issues/17

[nicolai86]

I'll merge the dependency update as all tests are green:

make testacc
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test $(go list ./... |grep -v 'vendor') -v  -timeout 120m
?   	github.com/terraform-providers/terraform-provider-scaleway	[no test files]
=== RUN   TestAccScalewayDataSourceBootscript_Filtered
--- PASS: TestAccScalewayDataSourceBootscript_Filtered (3.09s)
=== RUN   TestAccScalewayDataSourceImage_Basic
--- PASS: TestAccScalewayDataSourceImage_Basic (10.98s)
=== RUN   TestAccScalewayDataSourceImage_Filtered
--- PASS: TestAccScalewayDataSourceImage_Filtered (10.33s)
=== RUN   TestAccScalewayIP_importBasic
--- PASS: TestAccScalewayIP_importBasic (2.80s)
=== RUN   TestAccScalewaySecurityGroup_importBasic
--- PASS: TestAccScalewaySecurityGroup_importBasic (3.53s)
=== RUN   TestAccScalewayServer_importBasic
--- PASS: TestAccScalewayServer_importBasic (104.71s)
=== RUN   TestAccScalewayVolume_importBasic
--- PASS: TestAccScalewayVolume_importBasic (3.64s)
=== RUN   TestProvider
--- PASS: TestProvider (0.00s)
=== RUN   TestProvider_impl
--- PASS: TestProvider_impl (0.00s)
=== RUN   TestAccScalewayIP_Count
--- PASS: TestAccScalewayIP_Count (5.27s)
=== RUN   TestAccScalewayIP_Basic
--- PASS: TestAccScalewayIP_Basic (16.49s)
=== RUN   TestAccScalewaySecurityGroupRule_Basic
--- PASS: TestAccScalewaySecurityGroupRule_Basic (8.33s)
=== RUN   TestAccScalewaySecurityGroup_Basic
--- PASS: TestAccScalewaySecurityGroup_Basic (3.83s)
=== RUN   TestAccScalewayServer_Basic
--- PASS: TestAccScalewayServer_Basic (134.10s)
=== RUN   TestAccScalewayServer_ExistingIP
--- PASS: TestAccScalewayServer_ExistingIP (96.15s)
=== RUN   TestAccScalewayServer_Volumes
--- PASS: TestAccScalewayServer_Volumes (95.17s)
=== RUN   TestAccScalewayServer_SecurityGroup
--- PASS: TestAccScalewayServer_SecurityGroup (113.20s)
=== RUN   TestAccScalewayVolumeAttachment_Basic
--- PASS: TestAccScalewayVolumeAttachment_Basic (418.10s)
=== RUN   TestAccScalewayVolume_Basic
--- PASS: TestAccScalewayVolume_Basic (4.23s)
PASS
ok  	github.com/terraform-providers/terraform-provider-scaleway/scaleway	1033.965s