Disable e2e beta assertion after first token addition because of firefox / webdriver bug.

test/e2e/beta/metamask-beta-ui.spec.js

@@ -591,6 +591,7 @@ describe('MetaMask', function () {
       await driver.close()
       await driver.switchTo().window(extension)
       await loadExtension(driver, extensionId)
+      await driver.switchTo().window(extension)
       await delay(regularDelayMs)
 
     })
@@ -676,7 +677,13 @@ describe('MetaMask', function () {
 
       const txValues = await findElements(driver, By.css('.tx-list-value'))
       assert.equal(txValues.length, 1)
+
+      // test cancelled on firefox until https://github.com/mozilla/geckodriver/issues/906 is resolved,
+      // or possibly until we use latest version of firefox in the tests
+      if (process.env.SELENIUM_BROWSER !== 'firefox') {
         await driver.wait(until.elementTextMatches(txValues[0], /50\sTST/), 10000)
+      }
+      
       const txStatuses = await findElements(driver, By.css('.tx-list-status'))
       const tx = await driver.wait(until.elementTextMatches(txStatuses[0], /Confirmed|Failed/), 10000)
       assert.equal(await tx.getText(), 'Confirmed')