optimize conda install

- use only defaults channel (had to remove ipdb for this)
- fix major versions

environment.yml

@@ -1,26 +1,24 @@
 ---
 name: environment
 channels:
-  - conda-forge
+  - defaults
 dependencies:
+  - cartopy=0
+  - coverage=6
+  - coveralls=1
+  - gdal=3
+  - ipython
+  - matplotlib=3
+  - mock=4
+  - netcdf4=1
+  - nose=1
+  - numpy=1
+  - pillow=9
+  - pip
   - python=3.7
-  - setuptools=60.1
-  - cartopy=0.20.1
-  - coverage=6.2
-  - coveralls=3.3
-  - gdal=3.4
-  - ipdb=0.13
-  - ipython=7.30
-  - matplotlib=3.5
-  - mock=4.0
-  - netcdf4=1.5
-  - nose=1.3
-  - numpy=1.21
-  - pillow=8.4
-  - pip=21
-  - python-dateutil=2.8
   - PyYAML<6.0
-  - scipy=1.7
-  - urllib3=1.26
+  - scipy=1
+  - setuptools
+  - urllib3=1
   - pip:
       - pythesint==1.6.6