Added unit tests, updated readmes, updated gitignore.

.gitignore

-cp2kparser.egg-info
 *.pyc
-nomadtoolkit/nomadtoolkit/metaviewer/frontend/static/frontend/node_modules
-nomadtoolkit/nomadtoolkit/metaviewer/frontend/static/frontend/bower_components
+*.inp
+*.wfn
+test/examples/BASIS_SET
+test/examples/GTH_POTENTIALS
+parser/parser-cp2k/cp2kparser.egg-info

test/examples/Si_bulk_energy_force.inp

-&GLOBAL
-  PROJECT Si_bulk8
-  RUN_TYPE ENERGY_FORCE
-  PRINT_LEVEL MEDIUM
-&END GLOBAL
-&FORCE_EVAL
-  METHOD Quickstep
-  &SUBSYS
-    &KIND Si
-      ELEMENT   Si
-      BASIS_SET DZVP-GTH-PADE
-      POTENTIAL GTH-PADE-q4
-    &END KIND
-    &CELL
-      A     5.430697500    0.000000000    0.000000000
-      B     0.000000000    5.430697500    0.000000000
-      C     0.000000000    0.000000000    5.430697500
-    &END CELL
-    &COORD
-      Si    0.000000000    0.000000000    0.000000000
-      Si    0.000000000    2.715348700    2.715348700
-      Si    2.715348700    2.715348700    0.000000000
-      Si    2.715348700    0.000000000    2.715348700
-      Si    4.073023100    1.357674400    4.073023100
-      Si    1.357674400    1.357674400    1.357674400
-      Si    1.357674400    4.073023100    4.073023100
-      Si    4.073023100    4.073023100    1.357674400
-    &END COORD
-  &END SUBSYS
-  &DFT
-    BASIS_SET_FILE_NAME  BASIS_SET
-    POTENTIAL_FILE_NAME  GTH_POTENTIALS
-    &QS
-      EPS_DEFAULT 1.0E-10
-    &END QS
-    &MGRID
-      NGRIDS 4
-      CUTOFF 300
-      REL_CUTOFF 60
-    &END MGRID
-    &XC
-      &XC_FUNCTIONAL PADE
-      &END XC_FUNCTIONAL
-    &END XC
-    &SCF
-      SCF_GUESS ATOMIC
-      EPS_SCF 1.0E-7
-      MAX_SCF 300
-      &DIAGONALIZATION  ON
-        ALGORITHM STANDARD
-      &END DIAGONALIZATION
-      &MIXING  T
-        METHOD BROYDEN_MIXING
-        ALPHA 0.4
-        NBROYDEN 8
-      &END MIXING
-    &END SCF
-  &END DFT
-  &PRINT
-    &FORCES ON
-    &END FORCES
-  &END PRINT
-&END FORCE_EVAL