feat(colo17): fetch prices automatically

packages/colo17/priceFetch.js

@@ -0,0 +1,24 @@
+const CoinGecko = {
+  keyRange: 'priceKey',
+  priceApi: 'https://pro-api.coingecko.com/api/v3/simple/price'
+};
+
+/**
+ * ack: https://www.coingecko.com/en/api/documentation
+ */
+function FetchPrice(token='agoric', vs='usd') {
+  console.warn('AMBIENT: UrlFetchApp');
+  const { fetch } = UrlFetchApp;
+  console.warn('AMBIENT: SpreadsheetApp');
+  const doc = SpreadsheetApp.getActive();
+  const apiKey = doc.getRangeByName(CoinGecko.keyRange).getValue();
+
+  const url = `${CoinGecko.priceApi}?ids=${token}&vs_currencies=${vs}&x_cg_pro_api_key=${apiKey}`;
+
+  const resp = fetch(url,
+   { headers: {accept: 'application/json'}});
+  const data = JSON.parse(resp.getContentText());
+  // console.log(data);
+  const price = data[token].usd;
+  return price;
+}