setup: temporary pin dependency for keepkey compatibilty

setup.py

@@ -9,8 +9,11 @@ setup(
     author_email='roman.zeyde@gmail.com',
     url='http://github.com/romanz/trezor-agent',
     packages=['trezor_agent', 'trezor_agent.device', 'trezor_agent.gpg'],
-    install_requires=['ecdsa>=0.13', 'ed25519>=1.4', 'Cython>=0.23.4', 'protobuf>=3.0.0', 'semver>=2.2',
-                      'trezor>=0.7.6', 'keepkey>=0.7.3', 'ledgerblue>=0.1.8'],
+    install_requires=[
+        'ecdsa>=0.13', 'ed25519>=1.4', 'Cython>=0.23.4', 'protobuf>=3.0.0', 'semver>=2.2',
+        'trezor>=0.7.6', 'keepkey>=0.7.3', 'ledgerblue>=0.1.8',
+        'hidapi==0.7.99.post15'  # until https://github.com/keepkey/python-keepkey/pull/8 is merged
+    ],
     platforms=['POSIX'],
     classifiers=[
         'Environment :: Console',