fix(gas-estimator): Prevent float gas prices (UMAprotocol#2509)

Signed-off-by: Nick Pai <[email protected]>

packages/financial-templates-lib/src/helpers/GasEstimator.js

@@ -68,7 +68,10 @@ class GasEstimator {
 
   // Returns the current fast gas price in Wei, converted from the stored Gwei value.
   getCurrentFastPrice() {
-    return this.lastFastPriceGwei * 1e9;
+    // Sometimes the multiplication by 1e9 introduces some error into the resulting number,
+    // so we'll conservatively ceil the result before returning. This output is usually passed into
+    // a web3 contract call so it MUST be an integer.
+    return Math.ceil(this.lastFastPriceGwei * 1e9);
   }
 
   async _update() {