fix sample application errors caused by no longer supported db.t2.micro instance type

[szantopeter]

db.t2.micro is no longer supported, therefore CloudFormation definitions had to be updated to use db.t3.micro instead.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[szantopeter]

Additional to the actual issue the wellarchitected operational excellence workshop contains multiple issues, that should be fixed :

Issue 1

There are three links to create the environments like this :

us-west-2 : here
ap-southeast-2 : here
ap-southeast-1 : here

clicking on them will set an oudated fork as the GitRepositoryURL :

https://github.com/stephensalim/aws-well-architected-labs.git

instead of

https://github.com/awslabs/aws-well-architected-labs.git

Issue 2

The location of the bash script is outdated. Instead of

cd ~/environment/aws-well-architected-labs/static/2_prepare/Automating_operations_with_playbooks_and_runbooks/Code/scripts/

the correct location is

cd ~/environment/aws-well-architected-labs/static/Operations/200_Automating_operations_with_playbooks_and_runbooks/Code/scripts

I don't know where to open a PR for that so I am indicating it here

p.s.: the as I moved on with the workshop it contained many more errors, in the descriptions and the cloud formation templates

[szantopeter]

@awssteph @setheliot have you had a chance to look at this?