Test test_gmt_compat_6_is_applied leaves a gmt.conf file in the current directory

[seisman]

Description of the problem

To reproduce the bug, run:

mkdir tmp-test-dir-with-unique-name
cd tmp-test-dir-with-unique-name
pytest ../pygmt/tests/test_session_management.py

then you'll see a "gmt.conf" file in the tmp-test-dir-with-unique-name directory.

The "gmt.conf" file is generated by the test "test_gmt_compat_6_is_applied":

pygmt/pygmt/tests/test_session_management.py

Lines 30 to 34 in 809a888

	end() # Kill the global session
	try:
	with Session() as lib:
	# pretend that gmt.conf has GMT_COMPATIBILITY = 5
	lib.call_module("gmtset", "GMT_COMPATIBILITY 5")

At the end of the test, Lines 46-49 revert the GMT_COMPATIBILTY to 6. However, these codes only affect the gmt.conf in the session directory. The "gmt.conf" in the current directory is still untouched, with GMT_COMPATIBILITY set to 5.

pygmt/pygmt/tests/test_session_management.py

Lines 45 to 49 in 809a888

	finally:
	with Session() as lib:
	# revert gmt.conf back to GMT_COMPATIBILITY = 6
	lib.call_module("set", "GMT_COMPATIBILITY 6")
	end()

We should remove the "gmt.conf" from the current directory at the end of the test.