MNT: stop install wrong pyca package through pip

The correct package is on github: https://github.com/slaclab/pyca
and on coda: https://anaconda.org/conda-forge/pyca.

Need to switch to using correct package, which will
fix 'psp' plugin related tests. (psp is part of pyca)

Installing correct library and enabling test fixes issue where a user
downloads pydm and runs the tests with pytest cmd directly (instead of
run_tests.py), only to see 'no module named psp' failure. This failure seems to suggest
to user to 'pip install psp', which is the wrong package and confusing.

dev-requirements.txt

@@ -4,5 +4,4 @@ pytest-qt
 pytest-cov
 pytest-timeout
 p4p
-pyca
 pre-commit

pydm/tests/data_plugins/test_psp_plugin_component.py

@@ -1,3 +1,4 @@
+import time
 import functools
 import pydm.data_plugins.epics_plugins.psp_plugin_component
 from pydm.data_plugins.epics_plugins.psp_plugin_component import Connection
@@ -19,6 +20,11 @@ def __init__(self):
     def severity(self):
         return None
 
+    def timestamp(self):
+        secs = time.time()
+        nanos = time.time_ns()
+        return secs, nanos
+
 
 def test_update_ctrl_vars(monkeypatch: MonkeyPatch, signals: ConnectionSignals):
     """Invoke our callback for updating the control values for a PV as if we had a monitor on it. Verify

requirements.txt

@@ -5,3 +5,4 @@ pyqtgraph>=0.12.0
 qtpy
 scipy>=0.12.0
 six
+git+https://github.com/slaclab/pyca.git

run_tests.py

@@ -21,7 +21,6 @@
     # and a Windows PyCA build exists
     if os.name == "nt":
         args.append("--ignore=pydm/tests/data_plugins/test_p4p_plugin_component.py")
-    args.append("--ignore=pydm/tests/data_plugins/test_psp_plugin_component.py")
 
     print("pytest arguments: {}".format(args))