* Pin bats to the latest release (1.2.0)
This fixes the following error when running `make test` with bats
installed from its master branch:
/src/bats/libexec/bats-core/bats-exec-file:
line 192:
bats-exec-test:
command not found
The Makefile currently runs bats from its master branch. This can lead
to errors when bats is broken between releases, as is currently the case
with bats at the following commit:
bats-core/bats-core@b615ed8f75
Instead, use the latest release of bats, which is 1.2.0 (2020-04-25).
* Pin bats to latest release on Travis CI