Change how leap second updates are checked

Check #34

1. Add build/ to gitignore and remove from github.
2. Do not check for leap_update in loop for every iteration, instead just check for max(JDUTC) before the loop runs, and then set leap_update = False for every iter.
3. Add timeout of 10s for leap update from USNO

Sample script and unittest checked.

Solar barycentric correction

1. Include barycentric correction for the Sun in get_BC_vel() and exposure_meter_BC_vel(), by using SolarBarycentricCorrection() function. We also include a ReflectedLightBarycentricCorrection() function for reflected light observations of Solar system objects to measure Solar RVs, based on the same principles as the Solar barycentric correcction. However, this last Reflected light routine has not been tested yet.
2. Switch from using Scipy constants to Astropy constants.
3. Cache File IO for Leap second management.
4. Predictive mode.
5. Include PhysicalConstants module

Incorporate unit testing

v0.2.3

Generate v0.2.3 dist

Version number confusion.

Fixed init and setup file

Minor bug fixes and clean up

1. Change the sample script values to account for new Gaia coordinates. The sample script should be run after installation to check for the script running fine. It compares the results against hard coded values. These hard coded values needed to be changed.
2. Change vestigial documentation for JDUTC to BJDTDB converter.
3. Mask out values queried from SIMBAD. Filter by inequality greater than 1e10.

New version - check previous release description

Change version number in setup.py

Making the Zenodo DOI version independent for posterity

v0.2.1.1

Merge branch 'master' of https://github.com/shbhuk/barycorrpy

Debugging earlier version for bulk motion correction

Bug in bulk motion correction. Error ~ 0.1 m/s for high bulk motion stars. Fixed. Check Issue - #23

Changes made to base version

Changes detailed in wiki - What's new in v0.2 section.

Testing version for Barycorrpy

To iron out the bugs!