Add Google Cloud e2-micro free-tier info to README

[apivovarov]

Google Cloud e2-micro VM instance is ALWAYS FREE in us-west1, us-central1 and us-east1 regions.

Includes 1GB RAM, 30GB disk and 1 GB Outbound network traffic.

https://cloud.google.com/free/docs/free-cloud-features#compute)

[apivovarov]

@TinCanTech, FreeTrial is 90 days

But Free Tier is different. Free Tier is ALWAYS FREE (even after 12 months).

Free Tier usage limits includes: 1 non-preemptible e2-micro VM instance per month in one of the following US regions:

• Oregon: us-west1
• Iowa: us-central1
• South Carolina: us-east1

Plus 30 GB-months standard persistent disk Plus 1 GB network egress from North America

More Info https://cloud.google.com/free/docs/free-cloud-features#free-tier-usage-limits

@Nyr What you think? Single e2-micro with 30GB disk is ALWAYS FREE in Google Cloud