FIX: Update CIs (#240)

Author: larsoner

environment.yml

@@ -16,11 +16,11 @@ dependencies:
 - pytest-cov
 - flake8
 - pygments
+- traits
+- traitsui
+- pyface
 - pip:
-  - "https://api.github.com/repos/enthought/traits/zipball/a99b3f64d50c5f7f28ffc01bf69419b061f9e976"
-  - "https://api.github.com/repos/enthought/pyface/zipball/6a0cac149d56293482bb828a7d98122667c773be"
-  - "https://api.github.com/repos/enthought/traitsui/zipball/e366ad3886d3c39bedb96e83bab447d31c4ab725"
-  - "https://api.github.com/repos/enthought/mayavi/zipball/master"
+  - mayavi
   - nibabel
   - pytest-sugar
   - pytest-faulthandler