add ses smpt password to ssm, add ssm base path option

[sebastianmacarescu]

what

• Add option to change the SSM base path under which credentials are stored
• Store ses_smtp_password_v4 in SSM

why

• Even if the IAM users are global per account often times there is a need to separeate them per environment (dev, staging). By adding the ssm_base_path parameter we can have a better SSM hierarchy. Example: /dev/system_user/tc-dev-s3 and /staging/system_user/tc-staging-ses
• Also having the ses_smtp_password_v4 stored in SSM will allow better integration with CI systems when deploying applications (rather than having a script to generate the password or read the terraform state)

references

• Link to any supporting github issues or helpful documentation to add some context (e.g. stackoverflow).
• closes #60

[sebastianmacarescu]

Can we get this merged?

[Gowiem]

/test all

[Gowiem]

@sebastianmacarescu can you run the following locally and then commit and push?

make init && make readme

[sebastianmacarescu]

@Gowiem I can't run that since I'm on windows. Let me know if I can help with anything else.

[Gowiem]

@sebastianmacarescu I had to pull your changes and fix the readme on my end since you couldn't. Reopened your changes as #61. We'll get that merged shortly.