removed pypy3 (pyephem does not compile)

.travis.yml

@@ -9,8 +9,7 @@ python:
   - "3.6-dev"  # 3.6 development branch
   - "3.7-dev"  # 3.7 development branch
   - "nightly"
-  - "pypy"
-  - "pypy3"
+  - "pypy" # python 2
 services:
   - redis-server
 # install dependencies
@@ -22,4 +21,6 @@ install:
 script:
   - pytest
   - cd docs
-  - make html
+  # build the docs on 2.7 and 3.6 (sphinx requires 2.7 or >=3.4)
+  - if [[ $TRAVIS_PYTHON_VERSION == 2.7 ]]; then make html; fi
+  - if [[ $TRAVIS_PYTHON_VERSION == 3.6 ]]; then make html; fi

README.md

@@ -40,8 +40,7 @@ versions:
 * Python 3.4
 * Python 3.5
 * Python 3.6
-* [pypy](https://pypy.org/)
-* [pypy3](https://pypy.org/)
+* [pypy](https://pypy.org/) (Python 2)
 
 ## Documentation