switch to a semver system

[prjemian]

the calendar based version numbering is troublesome for the publishing scripts due to inconsistent handling of leading zero characters in the version:

Using "aps-anl-dev" as upload username
[ERROR] File "/tmp/conda-bld/noarch/pyRestTable-2019.709.0rc1-*_0.tar.bz2" does not exist
Using Anaconda API: https://api.anaconda.org
Using "prjemian" as upload username
[ERROR] File "/tmp/conda-bld/noarch/pyRestTable-2019.709.0rc1-*_0.tar.bz2" does not exist
(bluesky) jemian@wow ~/.../eclipse/pyRestTable $ ll /tmp/conda-bld/noarch/pyRestTable-2019.709.*
/bin/ls: cannot access /tmp/conda-bld/noarch/pyRestTable-2019.709.*: No such file or directory
(bluesky) jemian@wow ~/.../eclipse/pyRestTable $ ll /tmp/conda-bld/noarch/pyRestTa*
/bin/ls: cannot access /tmp/conda-bld/noarch/pyRestTa*: No such file or directory
(bluesky) jemian@wow ~/.../eclipse/pyRestTable $ ll /tmp/conda-bld/noarch/
total 12M
drwxr-xr-x 10 jemian aesbc  145 Jul  9 18:52 .cache/
-rw-r--r--  1 jemian aesbc 2.3K Jul  9 19:09 index.html
-rw-r--r--  1 jemian aesbc  23K Jul  9 19:09 pyresttable-2019.0709.0rc1-py_0.tar.bz2
-rw-r--r--  1 jemian aesbc 1.6K Jul  9 19:09 repodata2.json
-rw-r--r--  1 jemian aesbc 1.3K Jul  9 19:09 repodata.json
-rw-r--r--  1 jemian aesbc  620 Jul  9 19:09 repodata.json.bz2
-rw-r--r--  1 jemian aesbc  12M Jul  9 18:52 spec2nexus-2020.0.2-h39e3cac_0.tar.bz2
(bluesky) jemian@wow ~/.../eclipse/pyRestTable $ python setup.py --version
/home/oxygen/JEMIAN/.conda/envs/bluesky/lib/python3.6/site-packages/setuptools/dist.py:472: UserWarning: Normalizing '2019.0709.0rc1' to '2019.709.0rc1'
  normalized_version,
2019.709.0rc1
(bluesky) jemian@wow ~/.../eclipse/pyRestTable $ python setup.py version
/home/oxygen/JEMIAN/.conda/envs/bluesky/lib/python3.6/site-packages/setuptools/dist.py:472: UserWarning: Normalizing '2019.0709.0rc1' to '2019.709.0rc1'
  normalized_version,
running version
keywords are unexpanded, not using
got version from VCS {'version': '2019.0709.0rc1', 'full-revisionid': '3a56b5494b308d94b7edd1c524716a6f34e20772', 'dirty': False, 'error': None, 'date': '2019-07-09T19:07:42-0500'}
Version: 2019.0709.0rc1
 full-revisionid: 3a56b5494b308d94b7edd1c524716a6f34e20772
 dirty: False
 date: 2019-07-09T19:07:42-0500
(bluesky) jemian@wow ~/.../eclipse/pyRestTable $ git tag
2019.0709.0rc1

next version will be 2020.0.0