Enable Travis Testing

[benharsh]

We ought to implement a small travis test to:

• verify the source location exists
• verify the TOML file:
  • is valid TOML
  • contains the required information

[ankushbhardwxj]

In addition to these checks, some other checks related to #9846

• git tag version formatting
• namespace collisions

[ben-albrecht]

I believe this can be closed by https://github.com/chapel-lang/mason-registry/pull/48 after we spend some time validating it works as expected...