test(integrate):add the test about the key mem_saver

Author: pxlxingliang

tests/integrate/107_PW_OBOD_MemSaver/INPUT

@@ -0,0 +1,33 @@
+INPUT_PARAMETERS
+#Parameters (1.General)
+suffix			autotest
+calculation     nscf
+ntype			1
+nbands			6
+symmetry		0
+pseudo_dir      ../tools/PP_ORB/
+read_file_dir   ./
+
+#Parameters (2.Iteration)
+ecutwfc			20
+scf_thr				1e-8
+scf_nmax			100
+
+#out_chg      1
+init_chg        file
+out_band            1
+out_dos            1
+pw_diag_thr                0.00001
+
+#Parameters (3.Basis)
+basis_type		pw
+
+#Parameters (4.Smearing)
+smearing_method		gauss
+smearing_sigma			0.002
+
+#Parameters (5.Mixing)
+mixing_type		plain
+mixing_beta		0.7
+
+mem_saver 1

tests/integrate/107_PW_OBOD_MemSaver/KPT

@@ -0,0 +1,5 @@
+K_POINTS
+2
+Line
+0.5 0.5 0.5 5
+0.0 0.0 0.0 1

tests/integrate/107_PW_OBOD_MemSaver/SPIN1_CHG

@@ -0,0 +1,19 @@
+ATOMIC_SPECIES
+Si 14 Si.pz-vbc.UPF
+
+LATTICE_CONSTANT
+10.2  // add lattice constant
+
+LATTICE_VECTORS
+0.5 0.5 0.0
+0.5 0.0 0.5
+0.0 0.5 0.5
+
+ATOMIC_POSITIONS
+Direct 
+
+Si	// Element type	
+0.0	// magnetism
+2	
+0.00 0.00 0.00 1 1 1
+0.25 0.25 0.25 1 1 1

tests/integrate/107_PW_OBOD_MemSaver/STRU

@@ -0,0 +1,2 @@
+Test the output of bands and dos with key word "mem_saver"
+

tests/integrate/107_PW_OBOD_MemSaver/jd

@@ -0,0 +1,3 @@
+totaldosref 1190.44
+totalbandref 243.274815
+totaltimeref 

tests/integrate/107_PW_OBOD_MemSaver/result.ref

@@ -29,6 +29,7 @@
 106_PW_PU_chargemixing
 107_PW_OB_outputbands
 107_PW_OD_outputdos
+107_PW_OBOD_MemSaver
 107_PW_outWfcR
 107_PW_outWfcPw
 108_PW_RE