Update getting started info for Conda users.

[ahaerpfer]

Some clarifications in doc/dev/getting-started.rst for setting up a Conda environment instead of a virtualenv.

[ged-jenkins]

Can one of the admins verify this patch?

[ged-jenkins]

Can one of the admins verify this patch?

[standage]

Jenkins test this please

[ahaerpfer]

• Is it mergeable?
• Did it pass the tests?
• If it introduces new functionality in scripts/ is it tested?
  Check for code coverage with make clean diff-cover
• Is it well formatted? Look at make pep8, make diff_pylint_report,
  make cppcheck, and make doc output. Use make format and manual
  fixing as needed.
• Did it change the command-line interface? Only additions are allowed
  without a major version increment. Changing file formats also requires a
  major version number increment.
• Is it documented in the ChangeLog?
  http://en.wikipedia.org/wiki/Changelog#Format
• Was a spellchecker run on the source code and documentation after
  changes were made?

[ged-jenkins]

Can one of the admins verify this patch?

[ged-jenkins]

Can one of the admins verify this patch?

[standage]

Please test this Jenkins

[mr-c]

Jenkins, okay to test

[standage]

Test this please, Jenkins

[standage]

@mr-c This PR was accidentally closed earlier. Could that explain why Jenkins is ignoring us?

[mr-c]

Jenkins, please test this

[mr-c]

@standage Possibly? I directly initiated a build on the CI website.