* gnu/packages/cobol.scm (gnucobol): Update to 3.1.2.
[arguments]: Add 'set-TERM phase before 'check to set the TERM environment
variable for tests that expect it.
* gnu/packages/cobol.scm (gnucobol)[arguments]: Add phase to place
test-suite tarball in test directory. Change test target.
[native-inputs]: Add perl.
[inputs]: Download test-suite tarball.