Add code coverage to CI

[maurolacy]

Closes #172.

Running this in all dev branches seems overkill. It also takes ~8 minutes to run.

[webmaster128]

Running this in all dev branches seems overkill. It also takes ~8 minutes to run.

I think it's worth it because if you have codecov set up, it tells you if your PR has enough diff coverage. I had this in CosmWasm/cosmwasm#1286 where the tool made me add more tests to pass the codecov checks.

[webmaster128]

Looks like a good start. I'd add a codecov config as otherwise you hardly have visibility of the results.

[maurolacy]

Looks like a good start. I'd add a codecov config as otherwise you hardly have visibility of the results.

Nice. I'll copy / adapt it from cosmwasm.

[webmaster128]

Also have a look at https://github.com/CosmWasm/cosmwasm/blob/main/codecov.yml, especially the first line avoids annoying GitHub comments from the codecov bot.

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (main@e19fc2c). Click here to learn what that means.
The diff coverage is n/a.

❗ Current head 966eab9 differs from pull request most recent head ef69301. Consider uploading reports for the commit ef69301 to get more accurate results

@@           Coverage Diff           @@
##             main     #715   +/-   ##
=======================================
  Coverage        ?   92.04%           
=======================================
  Files           ?       98           
  Lines           ?    13446           
  Branches        ?        0           
=======================================
  Hits            ?    12376           
  Misses          ?     1070           
  Partials        ?        0           

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[ueco-jb]

LGTM