Enable plot tests

Plot tests only take a second or two and with proper temp file
management they should not break the build on any CI system. There's no
reason to keep them disabled.

.travis.yml

@@ -42,7 +42,8 @@ script:
   - export NUMBA_DISABLE_JIT=1
   # Uncomment following line if web testing on travis breaks our build
   #- export CATE_DISABLE_WEB_TESTS=1
-  - export CATE_DISABLE_PLOT_TESTS=1
+  # Uncomment the following line if plot testing breaks our build
+  #- export CATE_DISABLE_PLOT_TESTS=1
   - py.test -v --cov=cate test
 
 after_success:

appveyor.yml

@@ -17,9 +17,10 @@ build_script:
   - conda list
   # For the unit-tests, disable Numba JIT, otherwise Coverage wont reach the actual Python code
   - set NUMBA_DISABLE_JIT=1
-  # Uncomment following line if web testing on travis breaks our build
+  # Uncomment following line if web testing on appveyor breaks our build
   - set CATE_DISABLE_WEB_TESTS=1
   # geopandas in tests break the build on appveyor (maybe the problem of gdal?)
   - set CATE_DISABLE_GEOPANDAS_TESTS=1
-  - set CATE_DISABLE_PLOT_TESTS=1
+  # Uncomment following line if plot testing on appveyour breaks our build
+  #- set CATE_DISABLE_PLOT_TESTS=1
   - py.test -v --cov=cate test

test-all.bat

@@ -1,6 +1,7 @@
 call activate cate
 set CATE_DISABLE_WEB_TESTS=1
-set CATE_DISABLE_PLOT_TESTS=1
+REM uncomment the following line if plot tests cause problems
+REM set CATE_DISABLE_PLOT_TESTS=1
 set CATE_DISABLE_GEOPANDAS_TESTS=1
 py.test test
 rem py.test test\core\test_workspace.py