goreleaser: Some adjustments

[tuxillo]

• Rework the Tag detection a bit
• Exit if build fails
• Use 'openssl md5' instead of md5sum which is not available in some non-Linux systems.

[suizman]

Merging

[iknite]

I believe there's a regression in master branch to v0.1

the output of git fetch -ap && git show-tree:

* ff51d824 (master, origin/master) Merge pull request #181 from tuxillo/goreleaser-1
| * f96dd806 (tag: v1.0.0-rc1) Fix Azure release pattern
| * 3c3a3b05 (origin/azure-pipelines-release) Update Azure Pipelines and release script
| * e3223991 (tag: v0.3.0-docs) Merge pull request #146 from jllucas/restore
| * e90d4b33 (tag: v0.2.4-docs) Fix: panic when version is not set in cmd.
| | * 1523582f (origin/dragonboat) WIP
| |/
| | * cf9514b1 (origin/demo) doc: Update README
| |/
| * b3e096e9 (tag: v0.2-alpha) Fix goreleaser environment variables
| | * 8b735da8 (origin/tampering) Update scripts to support MacOS execution
| | * 06127d8f (tag: tampering) update intro documentation
| |/
| * c4ea9d35 (tag: v0.2-M3) Update archive files
| * c44c8b42 (tag: v0.2-M2) Use incremental ports in tests to prevent address already in use
| * c1061353 (tag: v0.2-M1) Remove Mutexes and rename EdSigner to Ed25519Signer
|/
* 32380634 (tag: v0.1) README.md: Update instructions to follow current cli interface, misc fixes
* 4b8cf79a initial push

I believe it needs to be --rebased before merged to master

[iknite]

Something weird is happening to this command diff-ing between commits is OK maybe it's something @panchoh will like to dig into, but it's nothing to be worried. Thanks, guys

[suizman]

Something weird is happening to this command diff-ing between commits is OK maybe it's something @panchoh will like to dig into, but it's nothing to be worried. Thanks, guys

Some time ago we've rewrite the repo history in order to remove binary files. It's possible this causes the inconsistency. Please open an separate issue to explore this situation.