Update travis config [changelog skip] (#963)

* Update travis config to only setup hatchet when running hatchet [changelog skip]

Fix a bug in the hatchet tests, and allow previous builds to finish before running the next test

* Add logging when skipping hatchet tests

Only skip hatchet tests on a forked PR

* Build on Travis only for master branch

* Upgrade from trusty to bionic on Travis

spec/hatchet/python_spec.rb

@@ -31,6 +31,9 @@ describe "Default Python Deploy" do
           expect(app.output).to_not match("No such file or directory")
           expect(app.output).to_not match("cp: cannot create regular file")
 
+          # let the previous build finish
+          sleep(5)
+
           # Redeploy with changed requirements file
           run!(%Q{echo "" >> requirements.txt})
           run!(%Q{echo "flask" >> requirements.txt})
@@ -44,6 +47,9 @@ describe "Default Python Deploy" do
           expect(app.output).to_not match("No dependencies found, preparing to install")
           expect(app.output).to_not match("No change in requirements detected, installing from cache")
 
+          # let the previous build finish
+          sleep(5)
+
           run!(%Q{git commit --allow-empty -m next})
           app.push!