Added pytest-raises

Converted test_units to use parametrize

Some hacking of test_distances to use pytest features

Completed moving test_distances to pytest style

rewrote test_transformations into pytest style

make scipy and matplotlib full dependencies (MDAnalysis#1159)

scipy and matplotlib are imported at top in analysis

- updated all modules
- removed any code that guards against scipy or matplotlib import
- conforms to style guide https://github.com/MDAnalysis/mdanalysis/wiki/Style-Guide#module-imports-in-mdanalysisanalysis
- fixes MDAnalysis#1159
- fixes MDAnalysis#1361

removed conditional skipping of tests when scipy or matplotlib are missing

minor clean ups

.travis.yml

@@ -31,8 +31,8 @@ env:
     - MAIN_CMD="pytest ${PYTEST_LIST} ${PYTEST_FLAGS}; python ./testsuite/MDAnalysisTests/mda_nosetests ${NOSE_TEST_LIST} ${NOSE_FLAGS}"
     - SETUP_CMD=""
     - BUILD_CMD="pip install -v package/ && pip install testsuite/"
-    - CONDA_DEPENDENCIES="mmtf-python nose=1.3.7 mock six biopython networkx cython joblib nose-timer matplotlib scipy griddataformats pytest=3.1.2 pytest-cov=2.5.1"
-    - CONDA_ALL_DEPENDENCIES="mmtf-python nose=1.3.7 mock six biopython networkx cython joblib nose-timer matplotlib netcdf4 scikit-learn scipy griddataformats seaborn coveralls clustalw=2.1 pytest=3.1.2 pytest-cov=2.5.1"
+    - CONDA_DEPENDENCIES="mmtf-python nose=1.3.7 mock six biopython networkx cython joblib nose-timer matplotlib scipy griddataformats pytest pytest-cov pytest-raises"
+    - CONDA_ALL_DEPENDENCIES="mmtf-python nose=1.3.7 mock six biopython networkx cython joblib nose-timer matplotlib netcdf4 scikit-learn scipy griddataformats seaborn coveralls clustalw=2.1 pytest pytest-cov pytest-raises"
     # Install griddataformats from PIP so that scipy is only installed in the full build (#1147)
     - PIP_DEPENDENCIES=''
     - CONDA_CHANNELS='biobuilds conda-forge'

package/CHANGELOG

@@ -48,6 +48,9 @@ Fixes
   * Fixed dtype of numpy arrays to accomodate 32 bit architectures (Issue #1362)
   * Groups are hashable on python 3 (Issue #1397)
 
+Changes
+  * scipy and matplotlib are now required dependencies (Issue #1159)
+
 
 Changes
   * scipy and matplotlib are now required dependencies (Issue #1159)