Add .toBePositive (#29)

[amishshah]

What

Adding the currently unimplemented .toBePositive matcher

Why

Currently unimplemented

Notes

Housekeeping

• Unit tests
• Documentation is up to date
• No additional lint warnings
• Add yourself to contributors list (yarn contributor)

[codecov-io]

Codecov Report

Merging #56 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff          @@
##           master    #56   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files          46     48    +2     
  Lines         207    216    +9     
  Branches       28     30    +2     
=====================================
+ Hits          207    216    +9

Impacted Files	Coverage Δ
src/matchers/toBePositive/index.js	100% <100%> (ø)
src/matchers/toBePositive/predicate.js	100% <100%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 642924a...d6a0d47. Read the comment docs.

[mattphillips]

Good job @hydrabolt