chore(ci): another attempt to program in .travis.yml

.travis.yml

@@ -37,7 +37,7 @@ script:
 jobs:
   include:
   - node_js: '12'
-before_deploy: npm run apply-next-version
+after_success: npm run apply-next-version
 deploy:
   - provider: npm
     src: "."

utils/apply_next_version.js

@@ -2,12 +2,6 @@ const path = require('path');
 const fs = require('fs');
 const execSync = require('child_process').execSync;
 
-if (!process.env.TRAVIS_BUILD_NUMBER) {
-  console.log('ERROR: TRAVIS_BUILD_NUMBER is not defined in env!');
-  process.exit(1);
-  return;
-}
-
 // Compare current HEAD to upstream master SHA.
 // If they are not equal - refuse to publish since
 // we're not tip-of-tree.
@@ -25,7 +19,7 @@ let version = package.version;
 const dashIndex = version.indexOf('-');
 if (dashIndex !== -1)
   version = version.substring(0, dashIndex);
-version += '-next.' + process.env.TRAVIS_BUILD_NUMBER;
+version += '-next.' + Date.now();
 console.log('Setting version to ' + version);
 
 execSync(`npm --no-git-tag-version version ${version}`);