Fix failing behave tests (jrnl-org#447)

The keyring package broke backward compatibility in version 8.0 by
moving some keyring backends to another package, keyrings.alt, as
documented in the changelog [1].

This change broke behave tests which were trying to use
keyring.backends.file.PlaintextKeyring - no longer existing in keyring
package.

This commit adds the keyrings.alt package as dependency so that the
PlaintextKeyring class can be used.

[1] https://pythonhosted.org/keyring/history.html#id22

features/steps/core.py

@@ -5,7 +5,8 @@
 import codecs
 import json
 import keyring
-keyring.set_keyring(keyring.backends.file.PlaintextKeyring())
+import keyrings
+keyring.set_keyring(keyrings.alt.file.PlaintextKeyring())
 try:
     from io import StringIO
 except ImportError:

setup.py

@@ -146,6 +146,7 @@ def dist_github():
         "six>=1.6.1",
         "tzlocal>=1.1",
         "keyring>=3.3",
+        "keyrings.alt>=1.3",
     ] + [p for p, cond in conditional_dependencies.items() if cond],
     extras_require = {
         "encrypted": "pycrypto>=2.6"