Create new account in CircleCI using bitbucket. Go to Project → AddProject → Select your bitbucket project → Choose your language → Save.
Now your project with work whenever you’re updating in Bitbucket.
Go back to atlassian sourcetree and stage the Uncommitted changes to the build properties file. Press Control-Shift-C to commit, provide a comment and press the commit button. Afterward, press the push button in the toolbar and check the branch, then click OK to push.
We’ve already connected circleci to our Bitbucket project and we’re following our repo with circleci. Notice circleci already picked up the commit in seconds and runs the Deploy and Run All Tests for our code into the Salesforce Org credentials we provided in the dev.branch.properties. Check it out and give it a try! Hope you enjoy!