Add go-ethereum service

spec/services.yaml

@@ -340,3 +340,20 @@ services:
     host: feedback.gwei.cz
     server: frontier
     monitor: 41
+
+  - name: Go Ethereum (ETH)
+    repo: ethereum/go-ethereum
+    host: eth.gwei.cz
+    server: hex
+    monitor: 43
+    version_conf:
+      from:
+        url: https://eth.gwei.cz
+        options:
+          method: post
+          headers:
+            Content-Type: 'application/json'
+          body: '{"jsonrpc":"2.0","method":"web3_clientVersion","params":[],"id":67}'
+        query: $match(result,/^Geth\/v([^-]+)/)[0].groups[0]
+      to:
+        strategy: github_tags