Fix test/CI failures due to upstream changes

.travis.yml

@@ -91,7 +91,15 @@ notifications:
 before_script:
   - echo ./ci/install-julia.sh "$JULIA_VERSION"
   - ./ci/install-julia.sh "$JULIA_VERSION"
-  - if [ "$TRAVIS_OS_NAME" = "osx" -a "$PYTHON" = "python3" ]; then brew update; brew upgrade python || echo "Ignoring errors..."; fi
+  - if [ "$TRAVIS_OS_NAME" = "osx" -a "$PYTHON" = "python3" ];
+    then
+        brew update;
+        brew upgrade python || echo "Ignoring errors...";
+        if ! which $PYTHON;
+        then
+            PYTHON="$(ls -1 /usr/local/opt/python@3.*/bin/python3 | head -n1)";
+        fi;
+    fi
   - if [ "$TRAVIS_OS_NAME" = "osx" -a "$PYTHON" = "python2" ]; then brew update; brew list python@2 &>/dev/null || brew install python@2 || echo "Ignoring errors..."; fi
   # Ignoring errors from brew since it may actually be OK to do so.
   # Following which command will catch installation failure:

src/julia/magic.py

@@ -23,12 +23,16 @@
 import warnings
 
 from IPython.core.magic import Magics, line_cell_magic, magics_class
-from IPython.utils import py3compat as compat
 from traitlets import Bool, Enum
 
 from .core import Julia, JuliaError
 from .tools import redirect_output_streams
 
+try:
+    unicode
+except NameError:
+    unicode = str
+
 try:
     from IPython.core.magic import no_var_expand
 except ImportError:
@@ -103,7 +107,7 @@ def julia(self, line, cell=None):
         Execute code in Julia, and pull some of the results back into the
         Python namespace.
         """
-        src = compat.unicode_type(line if cell is None else cell)
+        src = unicode(line if cell is None else cell)
 
         # We assume the caller's frame is the first parent frame not in the
         # IPython module. This seems to work with IPython back to ~v5, and

tox.ini

@@ -4,6 +4,7 @@ envlist = py3
 [testenv]
 deps =
     pytest-cov
+    coverage < 5
 extras =
     test
 commands =